Bismuth Vanadate Encapsulated with Reduced Graphene Oxide: A Nanocomposite for Optimized Photocatalytic Hydrogen Peroxide Generation

Abstract

The photocatalytic H2O2 production is a sustainable and eco-friendly process. Bismuth vanadate (BiVO4 or BVO) is a promising photocatalyst with a low band gap energy. Reduced graphene oxide (rGO) is known for promoting the transport of charges and preventing the recombination of photogenerated electron–hole pairs. This study proposes a synthesis method based on an electrostatic self-assembly approach for functionalizing BVO with GO for photocatalytic H2O2 generation. Different amounts of GO loading on BVO have been taken to assess and optimize the quality of xrGO–BVO (where x = 0.5, 1, 2, and 4 wt %) composites for effective H2O2 generation. H2O2 shows stability under acidic conditions; hence, the effectivity of the xrGO–BVO was tested using acids with different strengths. 1rGO–BVO exhibited efficient H2O2 generation in the presence of oxalic acid, promoting two-electron O2 reduction reaction with a good cyclic stability. A photocatalytic flow reactor study has also been presented to assess the feasibility of continuous H2O2 generation.

Efficient and Stable MoOX@Mo-BiVO4 Photoanodes for Photoelectrochemical Water Oxidation: Optimization and Understanding

“…The patterns confirm that the formation of highly crystalline BiVO 4 with a monoclinic crystal structure (JCPDS 14-0688) ,− did not change or any secondary peaks did not appear in the MoO X @2% Mo-BiVO 4 photoanode, indicating that molybdenum can be dissolved in the BiVO 4 structure. It should be noted that the XRD pattern of MoO X @2% Mo-BiVO 4 indicated slight shifts of the peaks in the low-2θ angle regions (please see the enlarged illustration, in the Supporting Information, Figure S4), which indicates the replacement of V 5+ (0.052 nm) with Mo 6+ (0.062 nm), leading to Mo doping in BiVO 4 . , …”

“…It should be noted that the XRD pattern of MoO X @2% Mo-BiVO 4 indicated slight shifts of the peaks in the low-2θ angle regions (please see the enlarged illustration, in the Supporting Information, Figure S4), which indicates the replacement of V 5+ (0.052 nm) with Mo 6+ (0.062 nm), leading to Mo doping in BiVO 4 . 38,39 The Raman spectra of the BiVO 4 and MoO X @2% Mo-BiVO 4 photoanodes are presented in Figures 3b and S5. The V−O bonds of MoO X @2% Mo-BiVO 4 indicated a peak at 822 cm −1 , which is lower in wavelength when compared with that of pure BiVO 4 (Figure S5).…”

Ultrahigh Performance H2O2 Generation by Single‐Atom Fe Catalysts with N/O Bidentate Ligand via Oxalic Acid and Oxygen Molecules Activation

“…[34] Meanwhile, the existence of peroxocarbonates can facilitate the desorption of H 2 O 2 from the surface of catalysts. [35] Furthermore, OA possesses excellent coordination ability, which can be easily adsorbed on metal-based catalysts to form metal-organic complexes. [36] The generation of metal-organic complexes can promote the activation by a ligand-to-metal charge transfer and thus facilitate the reductive reaction.…”

Electronic Tuning of SnO2 by rGO Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution

“…Photocatalysis is an eco-friendly and sustainable pathway for the generation of H 2 O 2 . In this process, the main concern is the lack of efficient photocatalysts, which have the efficiency to absorb a significant amount of solar light to generate an electron–hole pair with a substantial recombination rate . The photocatalytic generation of hydrogen peroxide can be achieved by the 2e reduction mechanism, as shown in the following equations. …”

“…Photocatalysis is an eco-friendly and sustainable pathway for the generation of H 2 O 2 . In this process, the main concern is the lack of efficient photocatalysts, which have the efficiency to absorb a significant amount of solar light to generate an electron–hole pair with a substantial recombination rate . The photocatalytic generation of hydrogen peroxide can be achieved by the 2e reduction mechanism, as shown in the following equations. O 2 + 2 H + + 2 e − → H 2 O 2 goodbreak0em1em⁣ E ( O 2 / H 2 O 2 ) = 0.424 0.25em normalV 0.25em vs . Ag / AgCl 2 H 2 O → O 2 + 4 H + + 4 e − goodbreak0em1em⁣ E ( O 2 / H 2 O ) = 0.974 0.25em normalV 0.25em vs . Ag / AgCl …”