Novel Ag/p-AgBr/n-BiVO₄ Plasmonic Heterojunction Photocatalyst: Study on the Excellent Photocatalytic Performance and Photocatalytic Mechanism

Abstract

A novel three-dimensional microspheres Ag/p-AgBr/n-BiVO4 plasmonic p–n heterojunction photocatalyst was successfully obtained for the first time; the photocatalytic performance of the as-prepared sample was systematically examined via the photocatalytic reduction of Cr6+ and oxidation of bisphenol S under visible-light irradiation. Among these samples, 3 mM-Ag/p-AgBr/n-BiVO4 exhibits the highest photocatalytic performances; the photocatalytic reduction and oxidation efficiency can be achieved at 76.9 and 98.8%, respectively. Enhancing photocatalytic performance is attributed to the increasing lifetime of the charge carrier confirmed by the results of time-resolved fluorescence spectra and photoelectrochemical measures. Moreover, based on the results of free radical scavenging activity test, and EPR experiments, we verify that h+ and •OH radicals are the main reactive species. Furthermore, the theoretical understanding of the underlying mechanism was also supported; we systematically calculated the energy band structure and Fermi level using the density functional theory approach. The results show that the matched positions of the CB and VB band edge between BiVO4 and AgBr are beneficial for efficiently separating electron–hole pairs. The strategy to form a three-dimensional microspheres plasmonic p–n heterojunction photocatalyst may offer a new strategy for applications in the field of solar energy conversion.

Photocatalytic Performance of NiS/CdS Composite with Multistage Structure

“…7−10 Currently, developing efficient photocatalysts has focus on some of the following aspects. (1) Noble metal/semiconductor photocatalysts: 11,12 they change the surface electron distribution and accelerate the carrier migration at the interface, enhancing the separated efficiency of photoinduced electrons and holes. (2) Nanomaterials with high electron mobility (such as graphene, MoS 2 , NiS, etc.)…”

“…Photocatalytic technology has developed rapidly in the energy fields due to its unique properties and has become the research focus that attracts much attention. − However, some scientific problems in photocatalysis are still difficult to solve, such as low quantum efficiency, limited solar utilization rate, and unclear photocatalytic reaction mechanism, which greatly restrict its application. − The key to solving these problems is still on the photocatalysts, and many attempts have been done to promote the photocatalytic performance by designing photocatalysts. − Currently, developing efficient photocatalysts has focus on some of the following aspects. (1) Noble metal/semiconductor photocatalysts: , they change the surface electron distribution and accelerate the carrier migration at the interface, enhancing the separated efficiency of photoinduced electrons and holes. (2) Nanomaterials with high electron mobility (such as graphene, MoS 2 , NiS, etc.)…”

Facile strategy for the fabrication of noble metal/ZnS composites with enhanced photocatalytic activities

“…It is worth noting that the intensity of the diffraction peak corresponding to the (111) crystal plane of ZnS in Ag/ZnS composites gradually decreases with the increased amount of Ag, owing to the high dispersion of Ag, indicating that the amount of Ag had an important inuence on the crystallinity. 32 In order to clearly observe the morphology of the samples, transmission electron microscopy (TEM) analyses were conducted as shown in Fig. 2.…”

Metal/semiconductor interfaces in nanoscale objects: synthesis, emerging properties and applications of hybrid nanostructures

“…In such a mechanism the solubility product of the AgBr determines the available concentration of silver for the reduction step, effectively transforming an AgBr NP into an Ag/AgBr dimer. 155 2.1.5 Solution-liquid-solid (SLS). The SLS growth mechanism (approach (III) in Fig.…”