High-valent Cu(III)-mediated Fenton-like catalysis on WC engineered Cu₂WS₄ for low H₂O₂ consumption and pH-universal...

The sustainability of Fenton-like catalysts is generally impeded by sluggish metal redox cycling and the high consumption of hydrogen peroxide (H₂O₂). Herein, we report a facile ethanol-assisted solvothermal method to synthesize Cu₂WS₄ functionalized with WC bonds (denoted as e-Cu₂WS₄). Compared to its hydrothermally fabricated counterpart (w-Cu₂WS₄), e-Cu₂WS₄ exhibits remarkably enhanced catalytic performance for degrading tetracycline (TC) at an ultralow H₂O₂ concentration (1 mM). Experimental and theoretical analyses indicate that the in situ generated WC bonds act as efficient electron transfer bridges, enhancing bulk electrical conductivity and accelerating the rate-determining Cu(II)/Cu(I) cycling. Notably, the e-Cu₂WS₄/H₂O₂ system exhibits exceptional catalytic performance over a wide pH range (4.18-10.38) and in complex aqueous environments, attributed to a non-radical pathway mediated by high-valent Cu(III) species. Toxicity bioassays with zebrafish and mung beans indicate the conversion of TC into low-toxicity byproducts, a finding corroborated by computational toxicity predictions. This work presents the first application of Cu₂WS₄ in Fenton-like processes, revealing that electronic modulation induces a Cu(III)-dominated non-radical route for highly efficient and low-consumption wastewater remediation.