Improving Photocatalytic Performance from Bi2WO6@MoS2/graphene Hybrids via Gradual Charge Transferred Pathway

Abstract

The charge transfer from the main catalyst to the cocatalyst is a key factor to enhance catalytic activity for photocatalytic nanocomposite materials. In order to enhance the charge transfer between Bi2WO6 and graphene, we inlet MoS2 as a “stepping-stone” into Bi2WO6 and graphene. Here, we report an effective strategy to synthesize ternary Bi2WO6@MoS2/graphene nanocomposite photocatalyst by a facile two-step hydrothermal method, which is afforded by assembling two cocatalysts, graphene and MoS2, into the Bi2WO6 matrix with a nanoparticle morphology as a visible light harvester. Compared with Bi2WO6/graphene, Bi2WO6/MoS2 and pure Bi2WO6, the Bi2WO6@MoS2/graphene ternary composites exhibit superior photocatalytic activity owing to an enhanced charge carrier separation via gradual charge transferred pathway. This work indicates a promising cocatalyst strategy for designing a more efficient graphene based semiconductor photocatalyst toward degradation of organic pollutants.

Heterostructured Ag/g‐C3N4/TiO2 with enhanced visible light photocatalytic performances

“…For instance, water pollution caused by organic dyes and their effluents is extremely harmful and difficult to clean through conventional sewage disposal. Semiconductor photocatalysts have shown high efficiencies and stabilities in industrial wastewater management by converting organic pollutants into comparatively harmless end products …”

“…Semiconductor photocatalysts have shown high efficiencies and stabilities in industrial wastewater management by converting organic pollutants into comparatively harmless end products. [7][8][9] Since Fujishima and Honda 10 reported the photogeneration of hydrogen using titanium dioxide (TiO 2 ) single crystal electrode under solar illumination, TiO 2 gained increasing attention in photocatalysis among various oxide semiconductors. However, the fast charge-carrier recombination rate of TiO 2 induced by its wide energy band gap (∼3.2 eV) limited its broad application.…”

Preparation of rGO/AgCl QDs and its enhanced photoelectrocatalytic performance for the degradation of Tetracycline

“…According to the calculation, BET surface area of AgCl QDs and rGO/AgCl QDs were 8.16 and 16.82 m 2 /g, respectively. It is clear that rGO plays an important role on increasing the specific surface area of the catalysts, which would provide more active sites, thus benefits the degradation performances of the samples …”

“…It is clear that rGO plays an important role on increasing the specific surface area of the catalysts, which would provide more active sites, thus benefits the degradation performances of the samples. 32,33 UV-vis diffuse reflectance tests (UV-vis DRS) of AgCl QDs and rGO/AgCl QDs are shown inFigure 6A. According to the UV/Vis absorption curves and Kubeka-Munk plots, the absorption of AgCl QDs is 391 nm with a band gap of 3.07 eV ( Figure S1B).…”

“…During the transfer process, because the CB value of AgCl QDs was more negative than that of O 2 /·O 2− potential, the electrons on the CB of AgCl QDs can directly reduce O 2 into •O 2− , which is a powerful oxidant for pollutant degradation. 33 Holes on the VB of AgCl QDs could directly oxidize pollutants into harmless products and could also oxidize OH − and H 2 O into •OH, which is also favorable for the removal of pollutants. 47,48 Therefore,·O 2− , h + , and •OH had played a vital role on the removal of TC.…”