Abstract Photocatalytic CO2 reduction to solar fuels is considered as a promising strategy to address the global warming and energy shortages. Herein, a novel method is proposed to prepare g-C3N4/ZnO nanocomposites via refluxing zinc salt methanol solution containing pre-formed g-C3N4 with KOH methanol solution as precipitating agent. Some in-situ grown ultrafine ZnO nanoparticles are decorated on ultrathin g-C3N4 layers with well-defined interface, which not only causes efficient charge transfer and separation, but also creates more active sites for CO2 adsorption and activation. The resultant g-C3N4/ZnO composites demonstrate significant enhanced CO2 photoreduction activity and selectivity for CH4 production under visible light irradiation, and the optimal g-C3N4/ZnO composite delivers the best overall photoactivity (158.4 μmol g-1 h-1) with CH4/CO production rates of 19.8/0.37 μmol g-1 h-1, which is 9.42 times higher than that of g-C3N4 alone. This work provides an ideal synthetic strategy for g-C3N4-based hybrid materials with highly efficient CO2 photoreduction.

中文翻译：

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在 g-C3N4 层上原位生长超细 ZnO 以在可见光下进行高活性和选择性的 CO2 光还原为 CH4

摘要 光催化 CO2 还原为太阳能燃料被认为是解决全球变暖和能源短缺的一种有前景的策略。在此，提出了一种以KOH甲醇溶液为沉淀剂，通过回流含有预先形成的g-C3N4的锌盐甲醇溶液制备g-C3N4/ZnO纳米复合材料的新方法。一些原位生长的超细 ZnO 纳米颗粒装饰在具有明确界面的超薄 g-C3N4 层上，这不仅导致有效的电荷转移和分离，而且为 CO2 吸附和活化创造了更多的活性位点。所得的 g-C3N4/ZnO 复合材料在可见光照射下表现出显着增强的 CO2 光还原活性和 CH4 生成选择性，最佳的 g-C3N4/ZnO 复合材料具有最佳的整体光活性 (158. 4 μmol g-1 h-1)，CH4/CO 生成率为 19.8/0.37 μmol g-1 h-1，比单独使用 g-C3N4 时高 9.42 倍。这项工作为具有高效 CO2 光还原的 g-C3N4 基杂化材料提供了理想的合成策略。