Green fabrication of aniline over mesoporous NiS/YVO4 S-type heterostructure photocatalyst under visible light exposure

Abstract

The photocatalytic hydrogenation of hazardous nitrobenzene (NTB) can efficiently and safely yield aniline (AN), which holds considerable economic significance. The systematic development of superb visible light-proceeded photocatalytic substances that effectively harness the sun spectrum is crucial. In this contribution, mesoporous YVO₄ nanostructured crystals were first assembled employing block copolymer-aided sol-gel protocol and then coupled with NiS nanoparticles (NPs) (4.0–16.0 wt%) through ultrasonic self-growth and calcination to design mesoporous step-type (S-type) NiS/YVO₄ (N/Y) heterostructure photocatalysts. A detailed characterization substantiated powerful interface interaction and effective S-type charge transmission in the designed heterostructured materials. Moreover, optical and photoelectrochemical experiments unveiled superb light harvesting and improved charge separation efficiencies. Thanking the building of the S-type heterostructure, the N/Y heterostructure materials recorded notable photocatalytic proficiency than pristine YVO₄. Specifically, under exposure to visible light for 50 min, the optimal material (12.0 % N/Y) at the best dosage (2.4 g/L) achieved 100 % selective phototransformation of NTB into AN with a rate constant (K) of 0.0696 min⁻¹, superior to pristine YVO₄ (0.0015 min⁻¹) by a factor of 46.4. The 12.0 % N/Y heterostructure also indicated superb cyclic stability, mostly retaining its remarkable efficacy over five consecutive runs. The positive influence of the catalyst content on the NTB photoreduction on 12.0 % N/Y was examined and affirmed by the catalyst dosage alteration. Additionally, based on Mott-Schottky (M − S) measurements, the pathway of charge migration for 12.0 % N/Y heterostructure was suggested. The current contribution offers estimable insights into developing highly effective and stable photocatalytic substances.