Development of low cost, highly efficient and non-noble metal photosystem is of a great significance for promoting the photoproduced carrier’s separation and acting as CO₂ reduction sites. Herein, non-noble metal catalysts of TiO₂ nanotubes (TNT) and hexagonal ZnIn₂S₄ nanosheets (ZIS) have been synthesized by simple hydrothermal methods and used for photoreduction of CO₂. After optimizing the TNT-loading ratio on ZIS, 10 wt% TNT/ZIS showed the best CO production activity (4.41 mmol g^–1 h^–1), which was 1.5 times higher than CO production rate of pristine ZIS. Especially, TNT/ZIS can present a stable CO evolving tendency during 72 h irradiation, producing regular activity and selectivity for 4 times of recycling test under solar-light irradiation. To reveal the underlying photocatalytic mechanism, the crystal structure, nanomorphology, light absorption, energy bandgap, element component and electrochemical behaviors of those obtained composite was characterized and analyzed. The results indicate that TNT/ZIS composite with glorious CO₂ reduction activity not only extends the responsive spectral range, but also pushed the transfer and separation of photoexcited electrons from ZIS to TNT and then to Co(bpy)₃²⁺ cocatalyst, in which Co(bpy)₃²⁺ can be reduced to Co(bpy)₃⁺ and re-oxidized to its original oxidation state during CO₂ conversion.

开发低成本、高效的非贵金属光系统对于促进光生载体的分离和作为CO ₂还原位点具有重要意义。_{在此，通过简单的水热法合成了TiO 2}纳米管（TNT）和六方ZnIn ₂ S ₄纳米片（ZIS）的非贵金属催化剂，并用于CO ₂的光还原。在优化 ZIS 上的 TNT 负载比后，10 wt% TNT/ZIS 表现出最佳的 CO 生产活性（4.41 mmol g ^–1 h ^–1)，比原始 ZIS 的 CO 产生率高 1.5 倍。尤其是TNT/ZIS在72 h辐照下表现出稳定的CO析出趋势，在太阳光辐照下进行4次循环试验时产生规律的活性和选择性。为了揭示潜在的光催化机理，对所得复合材料的晶体结构、纳米形态、光吸收、能带隙、元素成分和电化学行为进行了表征和分析。结果表明，具有优异CO ₂还原活性的TNT/ZIS复合材料不仅扩展了响应光谱范围，而且推动了光激发电子从ZIS到TNT再到Co(bpy) ₃ ²⁺助催化剂的转移和分离，其中钴(bpy) _{3在CO 2}转化过程中，2 ⁺可被还原为Co(bpy) ₃ ⁺并重新氧化为其原始氧化态。