Efficient regeneration of nicotinamide adenine dinucleotide (NADH) is of great significance for the application of oxidoreductase-catalyzed reactions. Photocatalytic regeneration is advantageous for the utilization of cheap, abundant, and clean solar energy. Graphitic carbon nitride (g-C₃N₄) has attracted wide attention due to its non-toxicity, wide range of precursors, suitable band gap, and superior chemical and thermal stability. In this work, mesoporous g-C₃N₄ (MPCN) was prepared using silica with different size as the template. The preparation process of MPCN was optimized and the effect of the template size on the structure and properties of MPCN were investigated. The results demonstrate that the smaller the template size, the larger the specific surface area of MPCN, and thus the better the photocatalytic performance. After optimization, the catalytic activity of MPCN with 7 nm silica as the template (MPCN-7) was 17.4 mM/(g min) and the NADH yield after 40 min was 70.6 %. MPCN-7 was also modified by 3-aminothiophene-2-carbonitrile (ATCN) and polyvinylpyrrolidone (PVP). Under same conditions, the catalytic activity of ATCN-MPCN, PVP-MPCN, and ATCN/PVP-MPCN was upgraded from 10.8 to 49.5, 16.4, 29.2 mM/(g min), respectively. The final yield of NADH rose from 66.9 % (40 min) to 76.3 % (12 min), 72.8 % (25 min) and 82.0 % (15 min).

烟酰胺腺嘌呤二核苷酸（NADH）的高效再生对于氧化还原酶催化反应的应用具有重要意义。光催化再生有利于廉价、丰富、清洁的太阳能的利用。石墨氮化碳(gC ₃ N ₄ )由于其无毒、前驱体种类广泛、合适的带隙以及优异的化学和热稳定性而受到广泛关注。本工作以不同尺寸的二氧化硅为模板制备了介孔gC ₃ N _{4 (MPCN)。}优化了MPCN的制备工艺，考察了模板尺寸对MPCN结构和性能的影响。结果表明，模板尺寸越小，MPCN的比表面积越大，光催化性能越好。优化后，以7 nm硅胶为模板的MPCN（MPCN-7）的催化活性为17.4 mM/（g·min），40 min后NADH收率为70.6%。MPCN-7 还经过 3-氨基噻吩-2-甲腈 (ATCN) 和聚乙烯吡咯烷酮 (PVP) 修饰。在相同条件下，ATCN-MPCN、PVP-MPCN和ATCN/PVP-MPCN的催化活性分别从10.8提高到49.5、16.4、29.2 mM/(g·min)。NADH 的最终产率从 66.9%（40 分钟）上升至 76.3%（12 分钟）、72.8%（25 分钟）和 82.0%（15 分钟）。