Isolated Ni atoms enable alkali-free photoreforming of waste polylactic acid plastic
H. Miao, Chengyang Feng, Jumanah Alharbi, Shouwei Zuo, Viko Ladelta, Ghassan S. Alshehry, Khalid Ruwaili, Hassan S. Al Qahtani, Deyan Luan, Wan‐Lu Li, Nikos Hadjichristidis, Huabin Zhang
Abstract
Although polylactic acid is a promising biodegradable plastic, its slow degradation under natural conditions, microplastic formation, and CO2 emissions during decomposition undermine its sustainability. Photoreforming offers a promising strategy for polylactic acid conversion; however, current methods suffer from sluggish kinetics and low selectivity. Here, we design a Ni single-atom catalyst anchored on CdS (Ni/CdS) to enable alkali-free photoreforming of real polylactic acid plastic waste under mild conditions. Ni single atom sites facilitate sequential cleavage of α-OH and Cα-H bonds, enabling efficient H2 evolution and significantly improving the yield and selectivity of polylactic acid conversion to H2 and pyruvic acid, achieving an apparent quantum efficiency of 46%. Furthermore, we successfully scaled up the synthesis of Ni/CdS and implemented a square-meter-scale reaction system, demonstrating stable outdoor photoreforming of real polylactic acid plastic waste under sunlight. This work paves a promising pathway for solar-driven upcycling of polylactic acid plastic waste. A Ni single-atom catalyst on CdS efficiently converts polylactic acid bioplastic into hydrogen and valuable chemicals using sunlight, offering a sustainable strategy for bioplastic waste recycling.