Visible Light‐Driven Heterojunction Array Based on Type‐I In 2 S 3 /In 2 O 3 for Selective Multi‐Gas Discrimination

Abstract Visible light‐activated chemoresistive gas sensors offer a promising solution for minimizing power consumption, preventing material degradation, and enabling room temperature operation. However, their lower photon energy compared to UV light results in slower recovery and reduced sensitivity to NO 2 , while detecting gases like volatile organic compounds and amines remains challenging. This work presents a visible light‐driven gas sensor array based on type‐I In 2 S 3 /In 2 O 3 heterostructure. The In 2 S 3 layer is uniformly deposited on In 2 O 3 nanorods, forming type‐I band alignment. Under blue light illumination, photoexcited electron‐hole pairs migrate to the In 2 S 3 surface, enhancing surface reactivity and enabling 56 times higher NO 2 response than pristine In 2 O 3 , with excellent selectivity, reliability, and humidity stability. Noble metal (Pd, Pt, and Au) decoration on the In 2 S 3 ‐In 2 O 3 array also allows truly selective detection of NO 2 , NH 3 , C 2 H 5 OH, and H 2 , which has not been reported previously for light‐activated gas sensors. This work introduces a new strategy to optimize visible light‐driven gas detection, advancing electronic nose technologies.