Abstract Electrocatalytic and photocatalytic reductions of CO2 into valuable chemicals or fuels have been considered a compelling strategy for environmental remediation and renewable energy conversion. In this field, SnO2 based materials have been widely applied as a promising electrocatalysts in the conversion of CO2 to formate, but the inferior catalytic efficiency is still the severe barrier for the application. In this study, a novel SnO2-based catalyst with Cu and N co-doping was designed for efficient and high-selective photoelectroreduction of CO2 into formate. XRD, FT-IR and XPS analyses demonstrated that (Cu, N) was doped into the lattice of SnO2 via replacing Sn and O, resulting the significant increase in the amount of oxygen deficiency from 27.18% to 36.72%. CV, LSV and EIS measurements proved that the (Cu, N) doping dramatically improved the photoelectrocatalytic performance of SnO2 based electrocatalysts for CO2 reduction. When the co-doping amount of (Cu, N) was 7 mol%, the Faradaic efficiency reached 54.97% with a lowest charge-transfer resistance and a fastest electron transfer rate. Furthermore, the DFT calculations revealed that the co-doping of Cu and N brought about the defect levels to narrow the band gap for the acceleration of the charge transfer, thereby improved the performances in electroreduction as well as photoreduction of CO2.

中文翻译：

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通过（Cu，N）共掺杂氧化锡的缺陷工程，用于电催化和光催化 CO2 还原为甲酸盐

摘要 将 CO2 电催化和光催化还原为有价值的化学品或燃料已被认为是环境修复和可再生能源转化的一种引人注目的策略。在该领域中，SnO2 基材料作为一种有前景的电催化剂在 CO2 转化为甲酸盐方面得到了广泛的应用，但较差的催化效率仍然是应用的严重障碍。在这项研究中，设计了一种具有 Cu 和 N 共掺杂的新型 SnO2 基催化剂，用于将 CO2 高效和高选择性地光电还原成甲酸盐。XRD、FT-IR 和 XPS 分析表明 (Cu, N) 通过取代 Sn 和 O 掺杂到 SnO2 的晶格中，导致缺氧量从 27.18% 显着增加到 36.72%。CV、LSV 和 EIS 测量证明 (Cu, N) 掺杂显着提高了基于 SnO2 的电催化剂对 CO2 还原的光电催化性能。当(Cu, N)的共掺杂量为7 mol%时，法拉第效率达到54.97%，电荷转移电阻最低，电子转移速率最快。此外，DFT 计算表明，Cu 和 N 的共掺杂带来了缺陷能级，从而缩小了带隙以加速电荷转移，从而提高了 CO2 的电还原和光还原性能。