Graphene Dispersed Bi₂WO₆ Nanosheets with Promoted Interfacial Charge Separation for Visible Light Photocatalysis

Abstract

Promoting photogenerated charge separation is the key and bottleneck step in photocatalysis, which mainly determines the efficiency of solar energy conversion. Reduced graphene oxide (rGO) has been emerging in the fields of physics, catalysis and material sciences due to its unique structures, high catalytic activity and tunability. In this work, we introduced rGO nanosheets as support to fabricate uniformly‐dispersed Bi2WO6 nanostructures onto the rGO surface under hydrothermal condition. The resulted rGO/Bi2WO6 composite exhibited superior performances in degradation of various kinds of environmental pollutants including dyes and phenol. Further electrochemical characterizations including open circuit potential, electrochemical impedance spectroscopy and electrochemical specific area indicated that incorporation of rGO evidently accelerated the interfacial charge separation and transfer. These improvements consequently contributed to largely exposed active sites and superior photocatalytic performance. Our work presented a facile strategy to tune the interfacial charge separation in semiconductor‐based photocatalysts using layered materials like graphene and its derivatives.

Roles of Graphene Oxide in Heterogeneous Photocatalysis

“…The unique 2D structure and amenable wet-chemistry processability of GO enable it to be used as a versatile template for the construction of nanomaterials with various morphologies. , Notably, GO can be simply eliminated by calcination in air, thus avoiding the utilization of harmful acids/base. , Furthermore, in some situations, a GO template can also be directly used to promote the electron transfer in the photocatalytic system, which not only avoids additional removal process but also enhances the photocatalytic activity of composites . Up to now, a variety of composite photocatalysts with specific morphologies have been prepared by using GO as 2D growth template. , For example, Han et al have used GO as a 2D growth template for in situ growth of 1D ZnO nanorod and the synthesis of RGO-ZnO-CdS ternary composites using CdS as photosensitizer (Figure a) .…”

“…The unique 2D structure and amenable wet-chemistry processability of GO enable it to be used as a versatile template for the construction of nanomaterials with various morphologies. 44 , 165 Notably, GO can be simply eliminated by calcination in air, thus avoiding the utilization of harmful acids/base. 166 , 167 Furthermore, in some situations, a GO template can also be directly used to promote the electron transfer in the photocatalytic system, which not only avoids additional removal process but also enhances the photocatalytic activity of composites.…”

Intervening Bismuth Tungstate with DNA Chain Assemblies: A Perception toward Feedstock Conversion via Photoelectrocatalytic Water Splitting

“…However, the photoactive performance of photoelectrodes can be tuned by optimizing the crystal structure, morphology, and doping with other elements, as well as by the nanocomposites with tailored co-catalysts. , Recently, bismuth (Bi)-based photocatalysts have been emerging in PEC water splitting with contemporary activities. − Moreover, Bi plays a crucial role in enhancing the photocatalytic activity of WO 3 in the visible region. ,, Although Bi-based materials have superior photocatalytic behavior, Bi 2 WO 6 ( n -type semiconductor) material still suffers few drawbacks and mainly occurs by high electron–hole recombination and slow water oxidation kinetics. , Numerous attempts have been made to avoid the above-mentioned setbacks for the betterment of the PEC process . In one such attempt, coupling with other metal oxides and combinations with biomolecules showed remarkable improvements toward PEC. , In many kinds of biomolecules, deoxyribonucleic acid (DNA) is one of the most favorable bioscaffold materials for the fabrication of nanoscale-based 1-D structures. − The presence of aromatic base pairs in DNA such as adenine (A), guanine (G), thymine (T), and cytosine (C) were interconnected with hydrogen bonds.…”