Polymeric carbon nitride (C3N4) has emerged as the most promising candidate for metal-free photocatalysts but is plagued by low activity due to the poor quantum efficiency and low specific surface area. Exfoliation of bulk crystals into ultrathin nanosheets has proven to be an effective and widely used strategy for enabling high photocatalytic performances; however, this process is complicated, time-consuming, and costly. Here, we report a simple bottom-up method to synthesize porous few-layer C3N4, which involves molecule self-assembly into layered precursors, alcohol molecules intercalation, and subsequent thermal-induced exfoliation and polycondensation. The as-prepared few-layer C3N4 expose more active sites and greatly enhance the separation of charge carriers, thus exhibiting a 26-fold higher hydrogen evolution activity than bulk counterpart. Furthermore, we find that both the high activity and selectivity for the oxidative coupling of amines to imines can be obtained under visible light that surpass those of other metal-free photocatalysts so far.

Cubic quantum dot/hexagonal microsphere ZnIn2S4 heterophase junctions were prepared and exhibited significantly higher visible-light photocatalytic hydrogen evolution performance than single cubic or hexagonal ZnIn2S4.

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A simple and practical manganese(iii)-promoted tandem phosphinoylation/cyclization of 2-arylindoles/2-arylbenzimidazoles with disubstituted phosphine oxides was developed.

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CdS quantum dot sensitized ZnFeO/ZnInS nanosheet stereoscopic films were synthesized through two sequential solvothermal processes and the ionic layer adsorption-reaction method. The hydrophilic ZnInS nanosheet stereoscopic film was pre-prepared to act as a suitable host material, and then ZnFeO nanoparticles and CdS quantum dots were uniformly decorated on the surface of the ZnInS nanosheet stereoscopic film to form a ternary heterostructure stereoscopic film. The band structure difference in the ternary heterostructure can promote the spatial separation and transport efficiency of photogenerated charge carriers. Meanwhile, the composite stereoscopic film has significant structural advantages and can provide a large amount of reaction active sites and outstanding visible light utilization. The superhydrophilic surface contributes to interface contact of catalyst/solution and gas detachment. These positive factors led to a significantly enhanced photocatalytic H evolution activity of the CdS/ZnFeO/ZnInS ternary heterostructure film in comparison with the pristine ZnInS and binary heterostructure film photocatalysts. The optimized CdS/ZnFeO/ZnInS ternary heterostructure film demonstrates the highest H production rate of 79.0 μmol h, which surpasses that of ZnInS by more than 3.2 times. This synthesis strategy can be applicable for the facile synthesis of other visible-light-driven composite film catalysts.

Photoreduction of CO2 into solar fuels is an appealing solution to simultaneously mitigate environmental problems and energy crisis, but photocatalyst activity and product selectivity remain challenging. Herein, ultrafine Pd nanoparticles immobilized in an imine-linked covalent triazine framework (Pd@Imine-CTF) are successfully prepared via a wet-chemistry approach. The resultant Pd@Imine-CTF exhibits a highly porous structure, which exposes more active sites and promotes CO2 adsorption and diffusion for photocatalysis. The ultrasmall Pd nanoparticles are confined and stabilized because of the strong interaction between Pd and pyridinic nitrogen atoms within Imine-CTF, which is beneficial for boosting the charge carrier separation and providing ideal sites for CO2 reduction reactions. Under visible-light irradiation, Pd@Imine-CTF displays excellent photocatalytic performance toward CO2 reduction, yielding CO and CH4 with evolution rates of 85.3 and 21.1 μmol g–1 h–1, respectively, and with a remarkable selectivity of up to 91.8%. This work provides a new protocol for the rational design of CTF-based photocatalyst composites for efficient CO2 conversion.

The nitrogen rich carbon nitrides from inorganic acid-derived HOF-liked precursors, which exhibit enhanced visible-light photocatalytic hydrogen evolution.