As early as 1972, the phenomenon that water can be split into oxygen and hydrogen gases (O2 and H2) by ultraviolet (UV) irradiation of a single-crystal titanium(IV) oxide (TiO2) anode was found by Fujishima and Honda(Fujishima and Honda 1972). Since then, a great deal of research has been devoted to semiconductor photocatalysis(Ravetz et al. 2019; Huang et al. 2021; Wang, Wang, et al. 2021). Thanks to nearly four decades of efforts by researchers worldwide, semiconductor photocatalysis have been playing important roles as an efficient advanced oxidation technology in many fields, such as environmental remediation, agricultural cultivation, energy conversion, and medical care(You et al. 2021; Kefeni and Mamba 2019; Rodríguez-González, Terashima, and Fujishima 2019). However, many of these catalysts are only active under UV irradiation because of their wide band gaps, such as TiO2(Zhou et al. 2020) and ZnO(Lee et al. 2019). Clearly, the narrow light response range of photocatalytic materials greatly limits utilization of the sunlight, as visible light accounts for 43% of the whole solar spectrum(Li, Xue, et al. 2020). Over past decades, in order to utilize solar energy as much as possible, many photocatalysts with high visible light activity have been developed (Qian et al. 2021; Zhang et al. 2021).
Recently, due to their unique crystal structure and suitable bandgap, bismuth (Bi)-based semiconductor photocatalysts have been widely used in the photocatalysis area (Han 2020; Zhang et al. 2022; Li, Kong, et al. 2020), such as bismuth molybdate(Huang et al. 2019), bismuth tungstate(Zhang et al. 2017; Zhang et al. 2018), bismuth hypohalites(Cao et al. 2021), bismuth vanadate(Huang et al. 2022), and bismuth oxide(Riente et al. 2021) (Bi2MoO6, Bi2WO6, BiOX (X = Cl, Br, or I), BiVO4, and Bi2O3, respectively). Among these, Bi2WO6 has attracted much attention due to its excellent visible light photocatalytic activities, unique layered structure, high thermal and photochemical stabilities, and environmental friendliness(Miao et al. 2021; Ma, Tian, et al. 2018). Bi2WO6 shows a visible-light absorption edge at ~ 470 nm with a band gap located at ∼2.8 eV. Bi2WO6 is constructed of perovskite-like [WO4]2− layers sandwiched between [Bi2O2]2+ layers, which is beneficial for separating photoexcited electron-hole pairs, and then enhancing photocatalytic performance(Jiao et al. 2019; Song et al. 2022).
Though the morphological control and atomic modulation of Bi2WO6 greatly improved its photocatalytic activity, the separation efficiency of photogenerated carriers is not satisfactory because there is only one component in the photocatalytic system and the charge recombination possibility remains high(Song et al. 2019). Fabrication of composite photocatalysts is considered as an effective modification strategy for improving the utilization of solar energy and promoting charge carrier separation(Gao et al. 2020; Shangguan et al. 2021). For now, the materials that metal-based materials, carbon-based materials, and semiconductors are chosen for coupling Bi2WO6 (Xue et al. 2019; Chen, Li, and Li 2020; Li, Chen, et al. 2020).
In recent years, a lot of articles have been published regarding the study of photocatalytic efficiency improvement of Bi2WO6 based nanomaterials(Chen et al. 2021; Li et al. 2021; Jiao et al. 2019). Bibliometric analysis can scientifically explain and analyze the research evolution process, research progress, and future development trend of this field through mathematical analysis and statistics of past articles published in this field(Ampese et al. 2022; Li, Jia, et al. 2022). The objectives of this study were to construct social network maps through bibliometric analysis of existing articles related to Bi2WO6-based nanomaterials. It is useful for understanding the history of Bi2WO6-based photocatalyst research area, current research hotspots, and future trends. Some suggestions and perspectives were also given by specifically discussing the hot issues of Bi2WO6-based photocatalyst.