It is highly desired to develop an efficient g-C₃N₄-based photocatalyst for energy production under visible-light irradiation. Herein, it is shown that the optimized g-C₃N₄ nanosheet-based photocatalyst could exhibit exceptional photocatalytic activities for H₂ evolution under visible-light irradiation, by ∼14-time improvement compared to that of bare g-C₃N₄ one. It is confirmed by the methods of transient-state surface photovoltage responses, transient-state PL spectra and electrochemical measurements that the exceptional photocatalytic activities are attributed to the unexpected synergistic effects of prolonging the charge lifetime and catalyzing H₂ evolution by coupling nanocrystalline anatase TiO₂ as a proper-energy platform to accept visible-light-excited electrons from g-C₃N₄ and by decorating a nano-sized noble metal as the co-catalyst respectively. Among three decorated noble metals (Ag, Au and Pt), to prolong the photogenerated charge lifetime is much meaningful for the used noble metal cocatalyst with weak catalytic function like Ag in H₂ evolution. Using nanocrystalline SnO₂ to replace TiO₂ is also applicable for the synergistic effect. Moreover, it is clarified by the designed experiment on photocatalytic CO₂ conversion to CD₄ in the presence of methanol in D₂O that the resource of evolved H₂ is mainly from the adsorbed H₂O other than the disassociated H⁺ from methanol.

迫切需要开发一种有效的基于gC ₃ N ₄的光催化剂，用于在可见光照射下产生能量。本文表明，优化的基于gC ₃ N ₄纳米片的光催化剂与可见的gC ₃ N ₄相比，在可见光照射下对H ₂的析出表现出优异的光催化活性，提高了约14倍。通过瞬态表面光电压响应，瞬态PL光谱和电化学测量的方法证实，出色的光催化活性归因于延长电荷寿命和催化H的出乎意料的协同效应。₂演化通过偶联纳米晶体锐钛矿的TiO ₂作为一个适当的能源平台接受来自GC可见光激发的电子₃ Ñ ₄和通过分别装饰纳米尺寸贵金属作为助催化剂。在三种装饰的贵金属（Ag，Au和Pt）中，延长光生电荷的寿命对于所用的H ₂析出中具有弱催化功能的贵金属助催化剂（如Ag）非常有意义。使用纳米晶SnO ₂代替TiO ₂也适用于协同作用。此外，通过设计的光催化将CO ₂转化为CD _4的实验得以阐明。在D ₂ O中存在甲醇的情况下，析出的H ₂的资源主要来自吸附的H ₂ O，而不是从甲醇中解离的H ⁺。