L-Cysteine boosts Fe2+/Fe3+ cycling in Fe-doped cellulose-derived hydrothermal carbonation carbon for enhanced peroxydisulfate activation and diclofenac degradation - Fanjiang Yang; Siwei Kang; Chao Zhang; Jiaqin Deng; Lu Du; Haoxiang Zhong; Meifang Li; Chunfang Tang; Yuan Ouyang; Zhiming Liu; Zhihang Yuan; Shaohan Li (Environmental Research, 2026)