Review—2D Graphene and Graphene-Like Materials and Their Promising Applications in the Generation of Hydrogen Peroxide

Abstract

The in situ formation of hydrogen peroxide, H2O2, is an attractive alternative to the current energy demanding and complex anthraquinone synthetic process. In this paper 2D materials, including graphene, graphitic carbon nitride (g–C3N4) and hexagonal boron nitride (hBN), are reviewed as electrocatalysts and photocatalysts for the selective two electron reduction of oxygen to give H2O2. Following an introduction to the complex oxygen reduction reaction, graphene is considered, followed by an account of g–C3N4 and hBN in generating H2O2. It is readily evident that graphene combined with carbon-based supports, doped with N, B or BN, decorated with single atom catalysts and prepared as aerogels can be employed to enhance the production of H2O2. Although the mechanism of this two electron oxygen reduction reaction remains unclear, mildly oxidised graphene is more effective and this is fortunate as fully reduced graphene is difficult to form and maintain. While hBN and g–C3N4 are much less studied as electrocatalysts, there is clear evidence that these 2D materials can be modified to give composites that favour the two electron oxygen reduction reaction, while g–C3N4-based materials are becoming well established as photocatalysts, effectively employing visible light, for the production of H2O2.

Structure-controlled graphene electrocatalysts for high-performance H2O2 production

“…25,26 Recently, metal-free carbon-based catalysts have shown great potential as alternative catalysts for H 2 O 2 production due to their low cost, high activity, tunability, and excellent stability. 17,[30][31][32][33][34][35] In particular, carbon catalysts containing certain surface oxygen and nitrogen groups have shown highly selective H 2 O 2 electrosynthesis in alkaline media. 17,35,36 For example, oxidized carbon nanotubes and reduced graphene oxides with oxygen functional groups on their surface showed high selectivity and catalytic activity for 2e À ORR.…”

Up-scalable emerging energy conversion technologies enabled by 2D materials: from miniature power harvesters towards grid-connected energy systems

“…Recently, however, there is a lot of progress in using single layer GRM in ion exchange membranes and hydrogen or methanol evolution catalysts for electrochemical applications. [343][344][345][346] Shinde et al recently reported an rGO-based composite membrane exhibiting high proton selectivity by concurrently avoiding any crossover of ionic or molecular species other than protons. 52 Central to this high performance was the dense packing of all components held by rGO sheets.…”

Recent Advances in Electrochemical Water Oxidation to Produce Hydrogen Peroxide: A Mechanistic Perspective

“…73 Other carbonbased materials with sp 3 structures such as diamond-like carbon (DLC) or hydrogen-carbonized hierarchically porous carbon (HPC) may demonstrate identical or superior results compared to BDD, with the latter being an interesting cost-effective option. 105,106,107,108 Modified graphene or graphene oxide electrodes may also be suitable carbon-based alternatives for the 2e − WOR, given their stability at high applied electrode potentials 109,110,111 and their proclivity to generate H 2 O 2 , albeit via the ORR. 112,113 Naturally, future mechanistic studies into H 2 O 2 electrochemical synthesis are not limited to investigations into catalyst surfaces.…”

“…BDD, which possesses a sp 3 carbon structure, has been reported as a promising catalyst candidate for the 2 e – WOR . Other carbon-based materials with sp 3 structures such as diamond-like carbon (DLC) or hydrogen-carbonized hierarchically porous carbon (HPC) may demonstrate identical or superior results compared to BDD, with the latter being an interesting cost-effective option. ,,, Modified graphene or graphene oxide electrodes may also be suitable carbon-based alternatives for the 2 e – WOR, given their stability at high applied electrode potentials ,, and their proclivity to generate H 2 O 2 , albeit via the ORR. , …”