Novel PVA/chitosan composite membrane modified using bio-fabricated α-MnO2 nanoparticles for photocatalytic degradation of cationic dyes

By integrating the benefits of poly vinyl alcohol (PVA) and chitosan (CS) with α-MnO2 nanoparticles (MNPs), a novel type of nano-polymer composite (PVA/CS-MNP) membrane was synthesized through a simple and facile casting method. In this proposed work, the membrane prepared was used for removal of organic textile dyes from their aqueous solutions. The as-synthesized PVA/CS-MNP membrane was examined using different analytical techniques such as Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM), and mechanical properties of material was also studied. Two cationic dyes, methylene blue (MB) and eosin yellow (EY), were chosen as template dyes to be removed from industrial waste water. These dyes were degraded by carrying out a reaction in which the synthesized membrane was used as a photocatalyst. The study of kinetics revealed that the reaction process followed pseudo-first-order kinetics. The efficiency of catalyst and the rate of reaction were also examined by varying parameters such as pH, initial concentration of dyes, and composition of membrane. The maximum efficiency of catalyst was observed at pH 12 as more than 95% of dyes degraded within 1 h of time span. The catalyst was found to be reusable as its efficiency did not deteriorate even after using it for several times. Such functional membrane having higher stability, low production cost, excellent efficiency to degrade dyes, and good recyclability are promising material for distinctly effective deletion of organic dyes from waste water.


Introduction
Over past two decades, water pollution has become an urgent threat to environment. Water pollution is majorly due to the presence of heavy metal ions, toxic dyes, and pigments used in industries. It has been reported that approximately 1.6 million tons of these dyes are produced per year, out of which 10-15% of dyes are being discharged into the water bodies (Hunger 2003). The degradation of these dyes discharged into water streams is very difficult; therefore, these dyes remain as such in the water bodies for a very long time (Carmen and Daniela 2012;Srinivasan and Viraraghavan 2010). The presence of dyes in aquatic habitat hinders the sunlight and oxygen to penetrate the water surface and thereby reduces the normal rate of photosynthesis as a repercussion of which the aquatic ecosystem deteriorates (Crini 2006). Not only is the aquatic environment being affected but the exposure of these dyes also has a fatal impact on human health. Several diseases like cancer, heart diseases, mutation, allergies, and tumors are the outcomes of consumption of waste water (Alver and Metin, 2012;Vakiliet al. 2014). Based on their chemical structure, dyes can be classified into three types: anionic (acid dyes); cationic (basic dyes); and non-ionic (disperse dyes) (Srinivasan and Viraraghavan 2010).
Several methods have been reported in the literature for the removal of these dyes from their aqueous solution such as oxidation technology, flocculation, and biological treatment ( Yao et al. 2015;Jayanthi and Suja 2016;Zhou et al. 2016;Tian et al. 2016;Gupta and Suhas 2009;Demirbas 2009). Although these techniques are being used for dye removal, there are certain drawbacks associated with all of these methods such as (i) lesser efficiency, (ii) higher energy requirements which makes it costly, and (iii) production of toxic by-products such as aromatic amines (including benzidine) which are carcinogenic in nature (Fishbein 1979).
On this account, there is a requirement to explore a method which is not only efficient but also environment-friendly and cost-effective. For these reasons, photocatalytic degradation of dyes has become the latest area of interest for researchers.
Among all these transition metal oxides, manganese oxide is one of the most significant sections of materials used as photocatalyst. Nanostructured manganese oxide has the ability to attain structural flexibility which makes it suitable to be used in the field of biosensors (Ou et al. 2017;Yuan et al. 2014), energy storage Lang et al. 2011), ion exchange (Liu et al. 2016, and as electrode materials used in batteries (Truong et al. 2012;Danish et al. 2020). The role of MnO 2 as catalyst for degradation of organic compounds helps in environmental remediation. α-MnO 2 is a semi-conductor having a band gap of 1.3 eV and, therefore, can effectively be used as a photocatalyst.
Over the past few years, the investigation of organic-inorganic nano-composite is being carried out extensively in order to merge the benefits of inorganic materials such as photocatalytic property and stability with organic polymers having advantages like processability and ductility (Elsayed et al. 2011).
Therefore, the use of polymers such as poly vinyl alcohol 1 (PVA), poly vinyl propylidene (PVP), chitosan 2 (CS), and cellulose with metal oxide nanomaterials is a recent approach of researchers for removing these toxic dyes from water bodies. These polymers are used as matrix for semiconductor materials (Alexandre and Dubois 2000;Tao et al. 2009;Vicentini et al. 2010;Zhang et al. 2011). The role of these polymers is to provide an interface for transfer of charge and obstruct leakage of ions in water. Among several polymers, the most extensively used polymer is chitosan because it is a non-toxic and biodegradable polymer (Synowiecki and Al-Khateeb 2003;Fong et al. 2015;Yaroslavov et al. 2021).
CS is a natural polysaccharide which is constituted of glucosamine and N-acetyl glucosamine (Ngah et al. 2011;Lim et al. 2021;Muinde et al. 2020). Although CS possess certain properties which are beneficial such as solubility in acid, tendency to attract negatively charged species (Martinova and Lubasova 2008) but it has certain limitations as well. Therefore, to improve its properties CS needs to be blend with some other polymers.
The blend of CS with an appropriate polymer (such as cellulose acetate, poly vinyl pyrrolidine and polyvinyl alcohol) results in the formation of highly reactive and mechanically stable film (Jayakumar et al. 2011;Shawky 2009). The mechanical stability of the membrane is also enhanced by incorporating nanoparticles into it (Ashori and Bahrami 2014;Delavar and Shojaei 2017;Ghaeeet al. 2010;Khabashesku et al. 2005;Khan et al. 2017;Vatanpour et al. 2012).
In this study, laboratory-synthesized α-MnO 2 nanoparticles 3 (MNPs) are used, for the first time, to alter the property of CS/PVA membrane. The synthesized membrane is biodegradable in nature and can be easily separated from water after treatment and then can be reused for several times after washing. The MnO 2 /CS-PVA film was used to remove cationic azo dyes such as eosin yellow 4 (EY) and methylene blue 5 (MB) and the kinetics of reaction along with its mechanism are also investigated.

Materials
CS was supplied by Molychem India Pvt. Ltd. Poly vinyl alcohol (PVA) was provided by LOBA Chemie. Acetic acid was supplied by Merck Life Science Private Ltd. Sodium hydroxide was procured from Molychem India Pvt. Ltd. Eosin yellow (molecular weight = 691.86 g/mol)) and methylene blue (molecular weight = 373.9 g/mol) were purchased from Fisher Scientific and Finar Chemicals, respectively.

Fabrication of membrane
MNPs were synthesized by reduction of KMnO 4 using leaf extract of Ficus retusa as mentioned in Srivastava and Choubey (2020). The plant extract was prepared by boiling thoroughly washed leaves (50 g) of F. retusa with 200 mL of deionized water for approximately 2 h. The extract obtained was then filtered using 0.2-μm membrane filter in order to remove impurities. In the typical synthesis, the aboveprepared plant extract solution was slowly added to 0.1 M solution of KMnO4 in the ratio of 1:2. The synthesis was carried out under constant stirring at room temperature. The solution prepared was subsequently boiled to obtain a paste which was black in color. Later, the black-colored paste was transferred into a ceramic crucible and heated in the muffle furnace at 800 °C for 2 h.
The synthesis of membrane was carried out by preparing two solutions: solutions A and B. Solution A was comprised of 4.3 g CS flakes and MNPs (varying concentration) dissolved in 200 mL of 2% v/v acetic acid solution kept in a water bath at 90 • C for 3 h and then stirred for 2 h at 600 rpm on a magnetic stirrer at 60 • C. Solution B was prepared by dissolving 8 g of PVA in 100 mL distilled water, and this solution was stirred at 600 rpm for 5 h at a temperature of 60 • C. The two solutions (solutions A and B) were then mixed and agitated at 600 rpm overnight in order to prepare a homogenous solution. The blend prepared at the end was then poured evenly into a petri dish and dried at 40 • C for 24 h. The membrane prepared was then separated by pouring 1 M solution of NaOH into the petri dish and keeping it aside for 1 h. The PVA/CS-MNP membrane was then washed several times with distilled water and then finally used for further experiments. Schematic representation is given in Fig. S1.
The following concentration of nanoparticles were used for the preparation of membranes Table 1.

Characterization
The characterization of MNP is mentioned in detail in the article (Srivastava and Choubey 2020). MNP samples used in this work are the same as those used for the study carried out in article (Srivastava and Choubey 2020).
The PVA-CS/MNP membrane was characterized using following analytical techniques: Fourier transform infrared (FTIR) spectroscopy was used to determine the functional groups coupled with the nanopolymer composite membrane. FTIR study was carried out using Spectrum 2-FTIR Spectroscopy, Perkin Elmer, within the range of 400 to 4000 cm −1 .
Mechanical properties of the fabricated membrane were determined using Universal Testing Machine (Tinius Olsen H5KL).
FESEM (Field Emission Scanning Electron Microscopy) images of the membranes were taken using Nova NanoSEM 450 instrument to examine the surface morphology of the membranes.

Photocatalytic activities
The photocatalytic activity of PVA/CS-MNP membrane was studied by carrying out the degradation of cationic dyes, viz. MB and EY. Dye solutions of varying concentrations were degraded using membranes incorporated with different concentration of nanoparticles (composites 1, 2, and 3). A catalyst of 0.50 g was separately added to 25 mL solution of MB and EY at 25 °C and initial pH of 8.0. The concentrations of MB solutions used for degradation was 10, 20, 30, and 40 mg/L, while EY dyes of concentration 10, 25, 50, and 100 mg/L were considered for the study. The suspensions were first kept in dark for about half an hour. These suspensions were then irradiated with sunlight under continues stirring until the solutions turned colorless. The mixture was stirred in order to prevent the catalyst from settling and also for maintaining continues exposure of catalyst to sunlight. The progression of the reactions was registered by quantifying the absorbance obtained through UV-Vis spectrophotometer (Lab India 3200). The course of reaction was also monitored using Cary Eclipse Fluorescence spectrometer (MY 14,270,004). Electrospray ionization mass spectrometry (ESI-MS) was carried out using Waters UPLC-TQD Mass spectrometer to validate the fact that dyes were completely degraded at the end of the reaction. The parameters for ESI-MS studies are as follows: ESI-MS was done in positive mode maintaining flow rate of drying gas = 7.01/min at 325 °C temperature and 30 psi pressure. The product was investigated in the range of 100-800 m/z.
The photocatalytic degradation efficiency of the composites was calculated using the equation mentioned below: where C 0 represents initial concentration of dyes and C e is the concentration of dye at equilibrium.

FTIR analysis
FTIR analysis is a non-destructive technique which was used to obtain the details of inorganic and organic components of the membrane fabricated in this work. FTIR-ATR of PVA, PVA/CS, and PVA/CS-MNP membrane was performed as seen in Fig. 1.
For pure PVA membrane, the band at 3301 cm −1 corresponds to -OH stretching vibration. The sharp peak at 2925 cm −1 is attributed to asymmetric CH 2 group Dye removal (%) = C 0 − C e C 0 * 100 stretching vibration. The peak obtained in the range of 1650-1430 cm −1 is due to the C = C stretching vibration of PVA. The peak at 1078 cm −1 and 835 cm −1 is because of the C-O stretching and C-C stretching vibration, respectively (Bonilla et al. 2014;El Miri et al. 2015).
In case of PVA/CS membrane, the incorporation of CS into the pure PVA membrane brought certain changes in the structure of PVA membrane. A peak at 1583 cm −1 was observed in case of PVA-CS membrane which was not seen in pure PVA corresponding to the N-H functional group of CS.
For PVA/CS-MNP membrane, bands at 3305, 2944, and 2122 cm −1 correspond to O-H, C-H symmetric, and asymmetric stretching, respectively. C = O and C = C stretching vibrations are assigned to the bands obtained 1739 cm −1 and 1640 cm −1 . The bands at 1428 cm −1 and 1369 cm −1 are ascribed to the vibration of C-H bending and C-H wagging. The next set of bands are located at 1218 and 1081 cm −1 owing to C-O stretching and C-H wagging acetate residue vibrations. The band located at 896 cm −1 is because of the rocking vibration of CH 2 group.
It is seen that the intensity of peak at 2925 cm −1 became weaker on incorporation chitosan into PVA and further reduced with addition of MNP into the matrix which is probably due to crosslinking between PVA and MNP. The peak obtained at 1078 cm −1 representing the C-O-C group got weaker which indicates that MNP could increase the degree of cross-linking of the composite membrane.

Mechanical properties of fabricated membranes
In order to explore the catalyst structure further, mechanical properties of the membrane were quantified. Figure 2 exhibits that the mechanical properties of PVA membrane are noticeably enhanced by the incorporation of CS which is then furthermore improved by incorporation of MNPs into the matrix of PVA/CS membrane. The improvement in the tensile strength, toughness, and strain was observed for lower concentration of nanoparticles being added to the membrane. On increasing the concentration of nanoparticles into the matrix of PVA/ CS membrane, a downfall in the mechanical properties  of membrane was observed. Therefore, it can be concluded that the optimum concentration for fabrication of membrane with good tensile strength is 0.1 g which is approximately 0.8 w/w%. Composite 1 exhibited an excellent tensile strength of 21.5 MPa, strain of approximately 21%, and toughness of 133.13 kJ/m 3 . Figure S2 shows the photographs of membranes of varying concentrations of nanoparticles within the membrane. The excellence achieved in the mechanical properties of membrane may be attributed to the homogeneous dispersion of MNPs within the matrix of polymer along with the suitable interfacial interactions among them as validated by FESEM and FTIR (Yang et al. 2010).

FESEM and EDX analysis of membranes
Furthermore, the FESEM analysis was carried out to determine the morphological structure of the photocatalytic membrane.

Decolorization of dyes
The photocatalytic activity of PVA/CS-MNP membrane was evaluated for degrading dyes such as EY and MB by subjecting the aqueous solution of dyes along with the prepared membrane to sunlight for certain time. Before exposing to sunlight, the reaction was kept in dark, but at the end of 30 min, there was no reduction in the intensity of peak, and hence, no adsorption took place on the surface of polymer-nano-composite membrane. The solution was thereafter kept in sunlight. The ability of the prepared membrane to decolorize the dye solutions (EY and MB) was studied at fixed concentration of 10 mgL −1 of dye solutions (EY and MB) using composite 1. The elementary observation of the process was the progressive change in the color of dyes with time. It was found that at the end of 2 h, both EY and MB dye solutions turned colorless from their respective orange and deep blue colors. The decrease in the concentration of dyes with time was calculated by examining the adsorption spectra of decolorization of EY and MB at different irradiation time using UV-Vis spectrometer. Figure 5 shows that the characteristic absorption band of EY and MB at 524 and 664 nm, respectively, decreased gradually and completely vanished after certain time intervals which indicates that the high molecular weight organic dyes are degraded to simpler products.

Degradation of dyes
Until now, the decolorization of dyes using PVA/CS-MNP membrane triggered by visible light has been discussed. In order to validate this observation and further investigate the process, fluorescence spectroscopy was carried out at different excitation wavelengths corresponding to the compound detected through adsorption maxima spectra obtained from UV-VIS spectroscopy data (Fig. 5). Fluorescence spectroscopy is an effective tool for monitoring of the mechanism involved in different chemical reactions (Lopez et al. 2013;Russo et al. 2009;Giustiniet al. 2013;Carstea et al. 2016;Travaglini et al. 2014). Figures 6 and 7 exhibit the fluorescence spectra of degradation of EY and MB dyes respectively mediated through the membrane composite 1. With this approach, it was ascertained that no intermediate product was formed during the degradation of EY dye. By exciting the solution of EY at three different wavelengths, i.e., 520, 500, and 480 nm, only a single species is identified that emits at 540 nm. The peak corresponding to 540 nm completely disappeared within 90 min. of exposure to sunlight in the presence of PVA/ CS-MNP membrane.
Similar to EY, MB dye solution was also excited at three different wavelengths, i.e., 660, 640, and 620 nm for which emission was obtained at 680 nm. The intensity of emission peak reduced with time and disappeared at the end of 2 h. No other peak was seen at any point of time during the degradation process.

Identification of end product of degradation of MB by ESI MS
In order to identify the end product of degradation, ESI MS of MB was recorded at the beginning and end of reaction ( Table 2). The mass spectral analysis of reaction at 0 min shows a peak at m/z (mass-to-charge ratio) 284 which   correspond to MB dye (Mahamallik and Pal 2016). The mass spectral analysis of the solution obtained at the end of reaction did not show the peak for parent MB molecule at m/z 284 which indicates that no MB was left in the solution and dye was completely degraded on to PVA-CS/MNP membrane. However, a peak at 226 m/z ratio is observed which is most probably due to loss of methyl groups and oxidative degradation of MB. A peak at m/z 301 may be attributed to hydroxylation of MB. A sharp peak is seen at 183 m/z value which agrees with the previously reported work (Rashid et al. 2018;Rauf et al. 2010). In the lower region, of spectrum, various peaks have been recorded at m/z of 102, 110, and 159 which clearly validates the degradation of MB due to the attack of OH radical.

Identification of end product of degradation of EY by ESI MS
The ESI-MS of EY was also recorded at the beginning and end of the reaction. Results found were similar as that of MB dye degradation. At the beginning of reaction, a peak at m/z ratio 648 is observed which disappears at the end of reaction showing the degradation of dye. At the end of reaction, peaks are seen at m/z 100, 126, and 148 which shows the complete degradation of dye using fabricated membrane as photocatalyst. irradiating the membrane to sunlight, firstly α-MnO 2 nanoparticles embedded into the matrix of membrane experiences a charge separation phenomenon which kicks the electrons from valence band (VB) to conduction band (CB) and ultimately creates a hole in the VB. The development of heterojunction causes transfer of photogenerated electrons and holes from CB to VB and VB to CB, respectively. During this transfer, electrons are captured by the PVA/CS membrane through semiconductor α-MnO 2 heterojunction which amplified the efficiency of charge separation dramatically. The photogenerated electrons and holes react with water and oxygen dissolved in water and produces highly reactive superoxide ( • O 2 − ) and hydroxyl radicals ( • OH). These radicals are highly reactive in nature and reacts with dye molecules and convert them to simple molecules of CO 2 , H 2 O, etc.

Effect of pH
pH of the solution has an influence on the process of photocatalysis which makes it necessary to optimize the pH for efficient degradation of dyes as well as for commercializing the material fabricated. The ionization state of the catalyst surface affects the optimization of pH. In case of PVA-CS/ MNP membrane, the surface of MnO 2 is positively charged in acidic medium while negatively charged in the basic medium. The optimal pH for degradation of MB and EY dyes was studied by varying the pH of reaction mixture from 2 to 12 using MB and EY dye concentration (10 mg L −1 )  and 0.5 g of composite 1 membrane. The normal pH of MB and EY dye aqueous solution was approximately 8. It was observed that the reaction was feasible only at pH above 7 and the rate of reaction increased tremendously on increasing the pH from 7 to 12. The enhanced activity of photocatalyst at higher pH is due to the cationic nature of dyes. These dyes are very easily ionized in basic medium to its cationic form. In addition, electrons are also available at higher pH to attract the positively charged dye molecule through electrostatic force of attraction. Therefore, at higher pH, MB and EY cations are adsorbed on to the surface of PVA-CS-MNP membrane having negatively charged surface. Moreover, at higher pH, cationic form of MB and EY dyes are reduced directly by highly reactive superoxide radical. The summary of optimization of pH is mentioned in Table 3.

Effect of concentration of MNP within membrane
With the objective of studying effect of concentration of nanoparticles on the efficiency of membrane to degrade dye solutions, three sets of nano-polymer composite (PVA/ CS-MNP) membranes were prepared. It was found that on increasing the concentration of nanoparticles incorporated into the membrane, the rate of reaction became slower (Figs. 8 and 9). The reason for it may be attributed to the agglomeration of nanoparticles on increasing the concentration within the matrix of membrane. The agglomeration of nanoparticles not only decreases the surface area but also reduces the penetration of light which lessens the photo activated volume and ultimately lowers the rate of reaction.

Effect of initial dye concentration
The effect of initial concentration of dyes (MB and EY) on photocatalytic degradation efficiency of PVA/CS-MNP membrane was studied by varying the concentration of dyes. The concentration of dye solutions used for study was 10, 20, 30, and 40 mgL −1 for MB and 10, 25, 50, and 100 mgL −1 for EY dye solutions. It was observed that percentage of removal of dye was higher in case of lowest concentration in a lesser span of time (Figs. 8 and 9). The lowest dye concentration (10 mgL −1 ) completely degraded at a higher pace. As the concentration of dyes (MB and EY) increased, the efficiency and rate of degradation decreased. The decrease in efficiency was due to the fact that at higher concentrations, the deep color of dyes reduced the excitation of electrons in catalyst. The deep color of dyes got adsorbed onto the surface of catalyst, and hence, a major portion of sunlight was taken up by the dark solution instead of reaching the catalyst. This observation is in accordance with those reported earlier by different researchers (Gnanaprakasam et al. 2015). Although more than 95% of dyes of all concentration degraded, the degradation of lesser concentrated dye solutions occurred faster as compared to high concentration dyes.

Kinetics of photocatalytic reaction
The photocatalytic degradation of dyes is expressed by pseudo-first-order kinetic model which is illustrated by plotting a graph between ln (C 0 /C t ) and irradiation time for all the synthesized materials used for degrading varying concentration of dyes. A straight line was obtained as shown in Figs. 10 and 11 which shows that the reaction process followed pseudo-first-order kinetics. Figure 8 and 9 also exhibits the percentage of removal of dye with time and it was found that the percentage of removal of dyes increased progressively with time. As mentioned above, composite 1 is the most effective PVA/CS-MNP membrane for degradation of dyes. The time required by composite 1 for degradation of dyes was found to be approximately 90 min for EY dye and 2 h for MB dye at pH 8. More than 95% of dyes got degraded within this time span. Table 4 shows the rate constant for the prepared membranes with respect to the concentrations of dyes (Both EY where C 0 is the initial concentration of dye; C t is the concentration of dye after time "t," and k is the rate constant. It was found that the rate constant was decreasing with increase in the concentration of MNPs incorporated into the PVA/CS-MNP membrane. The maximum values of rate constant were observed for the reactions involving composite 1 as catalyst ( Table 3). The value of rate constant also varied with initial concentration of dyes. As shown in Table 3.The increase in concentration of dyes leads to reduction in the value of rate constant.

Recyclability of catalyst
For practical utilization of catalyst, stability of catalyst is a significant parameter in the catalysis domain. In order to evaluate the stability of the fabricated membrane used as catalyst, the membrane was recycled 5 times for photocatalytic degradation of dyes (MB and EY) at pH 8. The membrane can be easily recovered as such at the end of the reaction, and therefore, there is no loss of catalyst amount after each cycle. It is shown in Fig. 12 that the removal of MB and EY dyes through the process of photocatalysis using PVA/CS-MNP membrane was successful even after 5 cycles of reuse. The removal efficiency could still reach up to 99% for both the dyes which indicates the good stability of the fabricated membrane.

Comparison of PVA/CS-MNP membrane with other photocatalysts
A comparison of efficiency of previously reported photocatalysts with the membrane presented in this work for degradation of EY and MB dyes is shown in Tables 5 and 6. PVA/CS-MNP membrane has the ability to degrade 99% of EY dye within 50 min. As shown in Table 5, similar to PVA/CS-MNP membrane, materials reported previously could successfully degrade EY dye up to 99%, but the rate of reaction using the material reported in this work is much faster as compared to previously reported materials.
The synthesized membrane was equally effective for degrading MB dye as well. PVA/CS-MNP membrane has the ability to remove approximately 99% of MB dye which is way too higher than other materials.

ln
C 0 C t = −kt

Conclusion
MNPs were successfully fabricated in the laboratory via green route, and then, the synthesized nanoparticles were incorporated into polymer membrane constituted of PVA along with CS to fabricate a nano-polymer composite membrane. In order to explore the synthesized material, the as-synthesized nano-polymer composite membrane was investigated for its ability to act as photocatalyst for degradation of cationic dyes such as MB and EY. The photocatalytic degradation of dyes was carried out under sunlight. On carrying out a detailed study on the process of removal of these dyes using the PVA/CS-MNP membrane, it was found that the membrane has the ability to completely degrade the targeted dyes. On optimizing the reaction conditions, it was found that the process of degradation of dyes was feasible only in basic medium, lowering the pH hinders the reaction process. Moreover, the concentration of nanoparticles was also optimized. It was observed that the increase in concentration of nanoparticles within the matrix of membrane decreases the effectiveness of reaction and increase in concentration of dye also reduces the rate of photocatalytic degradation. Therefore, it can be concluded that maximum removal of dyes at faster pace was obtained using composite 1 membrane at pH 12. In order to shed more light on the photocatalyst, its recycling efficiency was also explored and was found that the photocatalyst was successfully in removing approximately 99% of dyes even after reusing it for 5 times. The novel composite membrane is an ideal catalyst with excellent efficiency and reusability in various industrial reactions and waste water treatment.