Electronic Tuning of SnO<sub>2</sub> by rGO Nanosheets for Highly Efficient Photocatalytic Hydrogen Peroxide Evolution
Muhammad Irfan Ahmad, Shuo Chen, Hongtao Yu, Xie Quan
Abstract
Hydrogen peroxide (H 2 O 2 ) photocatalytic production from saturated oxygen and water in solar irradiation is an eco-friendly, sustainable, and safe process. Tin dioxide (SnO 2 ) is a promising photocatalyst with excellent light absorption and a low band-gap energy. Reduced graphene oxide (rGO) can promote charge separation and reduce photogenerated charge recombinations. Here, we represent different concentrations of the rGO dopant in SnO 2 that enhance the absorption in the visible range and reduce the energy band gap. rGO–SnO 2 successfully promotes water oxidation by 2e reduction of O 2, producing hydrogen peroxide. Composite materials enhance the H 2 O 2 yield in the presence of an organic electron donor (OED). The catalyst shows excellent endurance under different acidic conditions. Among all concentrations of rGO (0.5, 1, 2, and 4 wt %), 0.5 wt % rGO–SnO 2 shows a more efficient H 2 O 2 production in the presence of oxalic acid, as a stabilizer and an organic electron donor. Finally, we affirm a strategy to enhance photocatalytic hydrogen peroxide production regarding charge separation, light absorption, and surface catalytic reaction in an acidic environment. Our work provides valuable guidance to design efficient photocatalysts for H 2 O 2 generation by an insight mechanism.