Rational design of Pt-integrated SnNb2O6/Bi2MoO6 monolayer S-scheme heterojunction for efficient ethylene removal toward fresh produce preservation

Effective removal of ethylene (C 2 H 4 ) during fruit and vegetables storage and transport remains a critical challenge for post-harvest preservation. Although S-scheme heterojunctions can improve charge separation and redox capacity for ethylene degradation, their efficiency is still restricted by limited carrier transfer and sluggish oxygen activation. Here, we rationally designed a novel 2D/2D SnNb 2 O 6 /Bi 2 MoO 6 monolayer S-scheme heterojunction integrated with Pt co-catalyst to address these limitations. Density Functional Theory (DFT) calculations revealed the S-scheme charge transfer pathway, which was experimentally realized via electrostatic self-assembly followed by annealing-induced atomic interface bonding. Photodeposited Pt nanoparticles further promoted O 2 activation at reduction sites. The optimized Pt-50-SNOBMO achieved an outstanding visible-light-driven degradation rate (139.2 × 10 −3  min −1 ), 248.6 and 143.5 times higher than pristine SnNb 2 O 6 and Bi 2 MoO 6 , representing the best performance reported to date for ethylene removal. Extensive spectroscopic and microscopic analyses confirmed the robust interface interactions and S-scheme mechanism. This study provides new insights into heterojunction engineering and offers a promising strategy for advanced photocatalytic preservation technologies.