Construction of Interfacial Electric Field via Dual-Porphyrin Heterostructure Boosting Photocatalytic Hydrogen Evolution.

A dual-porphyrin heterostructure is successfully constructed by coupling tetrakis (4-carboxyphenyl) zinc porphyrin (ZnTCPP) with tetrakis (4-hydroxyphenyl) porphyrin (THPP). The high photocatalytic H2 evolution rate of 41.4 mmol h-1 g-1 is obtained for ZnTCPP/THPP under full spectrum, which is ≈5.1 and ≈17.0 times higher than that of pure ZnTCPP and THPP, respectively. The significantly enhanced activity is mainly attributed to the giant interfacial electric field formed between dual porphyrins, which greatly facilitates efficient charge separation and transfer. Meanwhile, similar conjugated structures of dual porphyrins also provide proper interface match and decrease interface defects, thus inhibiting the recombination of photoproduced carriers. By rationally combining the appropriate band structures and high-quality interfacial contact of dual porphyrins, this work provides a fresh insight into the interfacial electric field construction to improve the photocatalytic performance.