Zhanghui Xia, Longfei Lin, Xiao Chen, Jianxin Zhai, Cheng Xue, Shuaiqiang Jia, Jiapeng Jiao, Mengke Dong, Wanying Han, Xinrui Zheng, Ting Deng, Xinyu Zou, Chensheng Xian, Haihong Wu, Buxing Han
The application of solar photocatalysis under mild conditions offers a promising approach to mitigating plastic pollution. In this study, a Pt single-atom catalyst (Pt SAs) supported on a CdS–TiO 2 heterojunction (CTA) was synthesized to enable the efficient one-pot conversion of polylactic acid (PLA) into the high-value chemical alanine via integrated depolymerization, oxidation, ammonification, and reduction reactions. The Pt SAs-CTA catalyst achieved an outstanding alanine production rate of 12.1 mmol g cat –1 h –1 . Structural and optical characterizations, along with theoretical calculations, reveal that a two-channel electron transfer mechanism (TCETM) synergistically promotes charge separation and transport while suppressing electron–hole recombination, thereby enhancing the redox capability of the photocatalyst. Moreover, Pt SAs-CTA also exhibits excellent performance in the conversion of commercial-grade PLA under solar-simulated irradiation. This work elucidates the atomic-level charge dynamics of Pt single atoms in heterojunction photocatalysis and offers a viable strategy for upcycling plastic waste into value-added chemicals.