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In this work, we report an in situ construction of single-site Ti active centers on a carbon nitride surface during photocatalytic processes for one-pot chemoselective hydrogen transfer reduction of nitroaromatics and domino-type reaction using Cp2TiCl2 and −OH-enriched carbon nitride (OHCN) as precatalysts. Due to the selective adsorption of nitro and the promotion of photogenerated charge transfer by single-site Ti active species and the formation of Ti3+, the system can achieve an efficient chemoselective reduction of nitroaromatics containing various substituents, especially sensitive substituents (CC, CC, CO, CN, CN, C–X (X is halogen), etc.). The two processes of chemoselective reduction of nitroaromatics and oxidation of aromatic alcohols are photocatalytically coupled to form a complete photocatalytic cycle, which allows the simultaneous formation of two high-value-added products, aromatic amines and aromatic aldehydes. More valuable products like imines are obtained by effecting the reduction of the nitro moiety to −NH2 in the presence of aromatic alcohols that can react in a domino-type process. This work guides the in situ preparation of non-noble metallic single-site photocatalysts and provides a strategy for the photocatalytic synthesis of valuable organic compounds from nitroaromatics.

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Promoting charge separation, constructing active sites, and improving the utilization of metal atoms are very important for the design of efficient photocatalysts. A simultaneous loading of Ni2P cocatalysts on the inner and outer surfaces of mesoporous P‐doped carbon nitride hollow nanospheres (PCNHS) to construct a Ni2P@PCNHS@Ni2P photocatalyst is reported. Ni2P cocatalysts loading provides enough active sites on both the inner and outer surfaces for proton reduction, and the formed heterojunctions simultaneously promote the migration and separation of the photogenerated charges on the inner and outer surfaces. The photocatalytic reaction proceeds simultaneously on the inner and outer surfaces of Ni2P@PCNHS@Ni2P, which leads to a significantly improved photocatalytic water splitting performance and enhanced atomic utilization. Notably, the hydrogen evolution rate of Ni2P@PCNHS@Ni2P is 2.4 times higher than that of Pt‐loaded PCNHS. The findings guide the design of hollow nanostructured composites with high‐boosting photocatalytic performance.