This study reports on the photoelectrochemical reduction of CO₂ to methanol using Sn₃O₄ and reduced graphene oxide-tin oxide (rGO-Sn) nanocomposite synthesized through the microwave-assisted hydrothermal method. The resulting rGO-Sn nanocomposite exhibited enhanced activity and good stability during photoelectrochemical CO₂ reduction explained by Z-scheme electron transport. Graphene oxide (GO) has played a crucial role in the chemical composition and morphology of nanocomposites. The interaction between GO and Sn²⁺ ions during synthesis promoted the formation of the SnO₂ phase in the nanocomposite, thus generating mixed rGO/Sn₃O₄/SnO₂ phases (the rGO-Sn nanocomposite). Remarkable selectivity for CO₂/methanol conversion was obtained for both Sn₃O₄ and the nanocomposite at different potentials, in which the nanocomposite presented the highest conversion to methanol with a faradaic efficiency of 45 % at −0.3 V vs. Ag/AgCl. The improved activity of the nanocomposite was ascribed to the efficient use of solar energy (UV + visible light), to the decrease in electronic recombination in nanocomposite, which enabled an efficient electron-hole separation on the surface of the nanocomposite, and to the presence of rGO being combined with Sn₃O₄ and SnO₂ structures, which ensured a faster charge transport rate. This study reveals the potential of rGO-Sn nanocomposites as photocathodic material for solar-to-chemical energy conversion.

该研究报道了利用Sn ₃ O ₄和微波辅助水热法合成的还原型氧化石墨烯-氧化锡（rGO-Sn）纳米复合材料将CO ₂光电化学还原为甲醇。生成的rGO-Sn纳米复合材料在光电化学CO ₂还原过程中表现出增强的活性和良好的稳定性，这可通过Z方案电子传输来解释。氧化石墨烯（GO）在纳米复合材料的化学组成和形态中起着至关重要的作用。合成过程中GO和Sn ²⁺离子之间的相互作用促进了纳米复合材料中SnO ₂相的形成，从而生成混合的rGO / Sn ₃ O _4。/ SnO ₂相（rGO-Sn纳米复合材料）。对于Sn ₃ O ₄和纳米复合材料，在不同电势下均获得了显着的CO ₂ /甲醇转化选择性，其中纳米复合材料在-0.3 V电压下相对于Ag / AgCl表现出最高的甲醇转化率，法拉第效率为45％。纳米复合材料活性的提高归因于太阳能（UV +可见光）的有效利用，纳米复合材料中电子复合的减少，这使得能够在纳米复合材料表面上进行有效的电子-空穴分离以及存在rGO与Sn ₃ O ₄和SnO _{2结合的过程}结构，确保了更快的电荷传输速率。这项研究揭示了rGO-Sn纳米复合材料作为光阴极材料用于太阳能到化学能转化的潜力。