Visible-light-induced photodegradation of rhodamine B over nanosized Bi2WO6 has been observed. Bi2WO6 exhibited a high photoactivity to photodegrade rhodamine B in the central pH solution under visible irradiation (lambda > 420 nm). After five recycles for the photodegradation of rhodamine B, the catalyst did not exhibit any significant loss of activity, confirming the photocatalyst is essentially stable. The total organic carbon measurement displayed that a high degree of mineralization was achieved in the present photochemical system. The results of density functional theory calculation illuminated that the visible-light absorption band in the Bi2WO6 catalyst is attributed to the band transition from the hybrid orbitals of Bi6s and O2p to the W5d orbitals. The Bi2WO6-assisted photocatalytic degradation of rhodamine occurs via two competitive processes: a photocatalytic process and a photosensitized process. The transformation of rhodamine is mainly via the photocatalytic process. Kinetic studies by using electron spin resonance and the radical scavenger technologies suggest that *OH is not the dominant photooxidant. Direct hole transfers and O2*- could take part in Bi2WO6 photocatalysis. This study provided a possible treatment approach for organic pollutants by using visible light in aqueous ecosystems.

Single atomic layer nanosheet materials show great application potential in many fields due to their enhanced intrinsic properties compared to their counterparts and newly born properties. Herein, g-C 3 N 4 nanosheets with a single atomic layer structure are prepared by a simple chemical exfoliation method.The as-prepared nanosheets show a single atomic thickness of 0.4 nm and a lateral size of micrometers.The structure and photocatalytic properties of the as-prepared single layer g-C 3 N 4 are then studied.Compared with the bulk g-C 3 N 4 , single layer g-C 3 N 4 nanosheets show great superiority in photogenerated charge carrier transfer and separation. Accordingly, the photocatalytic H 2 production and pollutant decomposition activities and photocurrent generation of single layer g-C 3 N 4 nanosheets are much higher than those of the bulk g-C 3 N 4 , indicating the great application potential of single layer g-C 3 N 4 nanosheets in photocatalysis and photosynthesis.

A ZnO photocatalyst was hybridized with graphite-like C 3 N 4 via a monolayer-dispersed method. After hybridization with C 3 N 4 , the photocurrent of ZnO was enhanced by 5 times under UV irradiation and a photocurrent under visible light irradiation was observed. The photocatalytic activity of C 3 N 4 /ZnO under UV irradiation was increased by 3.5 times, the visible light photocatalytic activity was generated and the photocorrosion of ZnO was suppressed completely after ZnO was hybridized with C 3 N 4 . The enhancement in performance and photocorrosion inhibition under UV irradiation was induced by the high separation efficiency of photoinduced holes from ZnO to the HOMO of C 3 N 4 . Under visible light irradiation, the electron excited from the HOMO to the LUMO of C 3 N 4 could directly inject into the CB of ZnO, making C 3 N 4 /ZnO present visible light photocatalytic activity. The optimum synergetic effect of C 3 N 4 /ZnO was found at a weight ratio of 3%, which corresponded to a monolayer dispersion of C 3 N 4 on the surface of ZnO.

Square Bi 2 WO 6 nanoplates have been successfully synthesized by simple hydrothermal process. The effects of hydrothermal temperature and reaction time on morphologies and sizes of the nanoplates were investigated. These nanoplates are square geometric shapes having their basal plane as the (001) plane of orthorhombic Bi 2 WO 6 . On the basis of results of morphologies observation and selected area electron diffraction of series samples, a possible growth mechanism of the nanoplates is revealed. The square laminar shape could be attributed to anisotropic growth along the (001) plane, which is parallel to their intrinsic layer structure. UV-visible diffuse reflection spectra of the prepared Bi 2 WO 6 nanoplates indicate they had absorption in the visible region, but a blue shift appeared compared to their bulk counterparts. Their photocatalytic activities are determined by rhodamine B degradation under visible light irradiation (λ > 400 nm). The reaction constant (k) of the best quality Bi 2 WO 6 nanoplates is three times that of the sample prepared by solid-state reaction, which indicates much higher photocatalytic activities of the nanoplates performed under visible light irradiation.

Surface hybridization of TiO2 with graphite‐like carbon layers of a few molecular layers thickness yields efficient photocatalysts. Photoelectrochemical measurements confirm an electronic interaction between TiO2 and the graphite‐like carbon. A TiO2 photocatalyst with a carbon shell of three molecular layers thickness (∼1 nm) shows the highest photocatalytic activity which is about two times higher than that of Degussa P25 TiO2 under UV light irradiation. The mechanism of the enhanced photocatalytic activity under UV irradiation is based on the high migration efficiency of photoinduced electrons at the graphite‐like carbon/TiO2 interface, which is due to the electronic interaction between both materials. In addition, a high activity under visible light irradiation is observed after graphite‐like carbon hybridization. TiO2's response is extended into the visible range of the solar spectrum due to the electronic coupling of π states of the graphite‐like carbon and conduction band states of TiO2.