Enhanced separation and migration of photocarriers by carbon-supported In₂O₃@CuInS₂ heterojunction for superior photocatalytic nitrogen fixation

Abstract Nitrogen activation utilizing clean solar energy represents a promising way to break through the limitations of industrial ammonia production under harsh conditions. However, the limited interfacial charge transfer of photocatalysts is a rate-determining factor for photocatalytic nitrogen reduction reactions. In this study, a carbon-supported C-In 2 O 3 @CuInS 2 was synthesized through the calcination of MIL-68 (In) under argon and sequential solvothermal method. The resulting catalyst exhibited remarkable activity, achieving an ammonia production rate of 33.38 μ mol·g −1 ·h −1 , significantly surpassing the performance of C-In 2 O 3 (trace) and CuInS 2 (9.494 μ mol·g −1 ·h −1 ). Crucially, the experimental results show that photocatalysts with carbon support can greatly improve the separation and migration of photocarriers by making a comparison of ammonia yield and electrochemical testing of C-In 2 O 3 @CuInS 2 and In 2 O 3 @CuInS 2 . This work provides a foundational strategy for designing heterojunctions to improve photocatalytic nitrogen fixation by optimizing photogenerated carrier migration.