Electrostatic Self-Assembly of BiVO₄–Reduced Graphene Oxide Nanocomposites for Highly Efficient Visible Light Photocatalytic Activities

Abstract

It is commonly considered that the morphology and interface of semiconductor-reduced graphene oxide (rGO) composite photocatalysts play a crucial role in determining their photocatalyzing performance. Herein, we report on the design and synthesis of BiVO4-rGO nanocomposites with efficient interfacial contact by self-assembly of positively charged amorphous BiVO4 powders with negatively charged graphene oxide (GO), followed by a one-step GO reduction and BiVO4 crystallization via hydrothermal treatment. The as-prepared BiVO4-rGO nanocomposites exhibit high visible light photocatalytic efficiency for the degradation of model dyes, and are significantly superior to bare crystalline BiVO4 and BiVO4-rGO-U that is hydrothermally synthesized using the mixture of GO nanosheets and BiVO4 powders without modification of surface charge. Using multiple characterization techniques, we found that the enhanced photocatalytic performance of BiVO4-rGO arises from the synergistic effects between the microscopic crystal structure of BiVO4 with smaller particle size and more sufficient interfacial interaction between BiVO4 and graphene sheets, leading to increased photocatalytic reaction sites, extended photoresponding range, enhanced photogenerated charge separation, and transportation efficiency. This work may provide a rational and convenient strategy to construct highly efficient semiconductor-rGO nanocomposite photocatalysts with well-contacted interface toward environmental purification and solar energy conversion.

BiOBr/protonated graphitic C3N4 heterojunctions: Intimate interfaces by electrostatic interaction and enhanced photocatalytic activity

“…Lin et al demonstrated a novel anion-exchange strategy to prepare BiOI/BiOBr composite which greatly enhanced photocatalytic activity for the degradation of methyl orange (MO) [21]. Wang et al reported an electrostatic self-assembly of BiVO 4 /rGO composite via a simple surface charge method and enhanced photocatalytic activity [22]. Recently, our group successfully prepared a series of titania based photocatalysts by enwrapping heterogeneous semiconductors with titania nanosheets, which exhibited superior photocatalytic performance and stability [23,24].…”

Hydrothermal synthesis of FeWO4-graphene composites and their photocatalytic activities under visible light

“…FeWO 4 /graphene composites exhibited high capacity and excellent cyclic stability for both Li-ion and Na-ion batteries, using FeCl 3 ·6H 2 O, and Na 2 WO 4 ·2H 2 O as precursors [13]. Graphene-based composite materials have shown significant improvement in the electronic conductivity and transportation, resulting in good photocatalytic properties [14][15][16][17][18][19][20][21]. However, no literature has reported the photocatalytic properties of FeWO 4 -graphene composites as far as we know.…”

A simple route to significant enhancement of photocatalytic water oxidation on BiVO4 by heterojunction with SiC

“…BiVO 4 , with a band gap of 2.4 eV, is an OER catalyst under visible light irradiation because its valence band (VB) is more positive than the H 2 O/O 2 redox potential [8][9][10][11]. And it is also commonly utilized as an excellent visible-light photocatalyst http for pollutant degradation [12][13][14][15]. However, the nature of easy electron-hole recombination in BiVO 4 severely limits its function.…”