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The development of economical multiphase photocatalysts is a significant challenge in achieving large-scale industrialization. Rational catalyst design can help in achieving efficient, energy-saving, and green catalytic reactions, making it more feasible to screen potential catalyst candidates. In this paper, we have successfully developed a high-efficiency photocatalyst Cu-doped Cu2WO4(OH)2(CWOH-y, where y represents the molar ratio of copper tungsten source), which can catalyze the aerobic coupling reaction of amines to produce corresponding imines under visible light irradiation. N-benzylidenebenzylamine is synthesized under visible light at 25 °C with an 89 % yield. Under natural light at around 35 °C (mean light intensity of 50 mW/cm2), 94 % of the benzylamine is converted, and 97 % of the product is N-benzylidenebenzylamine. The catalyst exhibits high efficiency due to the synergistic effect of doped Cu, Cu2WO4(OH)2, and visible light. This combination generates a significant amount of superoxide free radicals and singlet oxygen when exposed to visible light. Furthermore, the catalyst demonstrates universality and stability with a wide range of amine derivatives. This study introduces a new environmentally friendly photocatalytic pathway for the synthesis of imines and emphasizes the potential applications of Cu2WO4(OH)2.

KTi3NbO9nanoparticles were fabricated viaa simple hydrothermal method with a post-calcination treatment. The nitrogen doping (N-KTi3NbO9) leads to a narrow band gap, which in turn facilitates efficiently catalysis of imine deamination under purple light that matches its absorption spectra. Furthermore, N-KTi3NbO9exhibits excellent performance in the tandem reaction of photocatalytic imine formation and deamination from various amines. The conversion of benzylamine was up to 100% with >85% benzaldehyde selectivity.

A high aniline yield was achieved by the combination of near-UV light as the driving force of nitrobenzene reduction and a ZnNb2O6surface as the product-selective controller. Here, a ZnNb2O6fibre, having a wide band gap and both acidic and basic sites, was exploited by a novel ion-exchange method to study the effect of the surface acidity and basicity of catalysts on the product selectivity under near-UV light irradiation without the interference of photo-generated carriers. ZnNb2O6showed the highest aniline yield compared to Nb2O5and ZnO. The results of experimental and theoretical calculations confirmed that the acidic sites on the surface of ZnNb2O6promoted the breakage of the N–O bond in the intermediate phenylhydroxylamine while the basic sites were attached to the dissociated hydrogen of isopropyl alcohol, resulting in high aniline selectivity.

To improve the photocatalytic performance of TiO2and make it easier to recycle, the titanosilicate@anatase core-shell micro-nanostructure photocatalysts were designed. The titanosilicate@anatase core-shell micro-nanostructure was fabricated by a two-step method: an acid-assisted hydrothermal treatment of the hydrogen-form natisite and a subsequent calcination. In the first step, the dissolution and recrystallization of Ti species led to the formation of TiO2shell over the titanosilicate; in the second step, the calcination not only facilitated the formation of Ti−O−Si bond, but also improved the crystallization of TiO2shell. The rutile TiO2was not detected even at 900 °C, which could be attributed to the strong interaction between TiO2nanocrystals and the titanosilicate core through Ti−O−Si bond at the interface. The formation of Ti−O−Si bond also changed the surface characteristic of the TiO2shell, which facilitated the enrichment of RhB dye molecules around the catalyst and induced the fast production of the O2•−. The collaboration of the core and the shell contributed to the quick degradation of RhB under visible light and the excellent recycling performance. The growth kinetics of the core-shell micro-nanostructure has been studied in detail, which provided a novel and facile synthesis strategy for the fabrication of TiO2micro-nanostructure easy to be recycled.