Addressing the dual challenges of limited gold resources and increasing environmental pollution, the sustainable recovery and functional upcycling of gold from electronic waste (e-waste) has emerged as a promising strategy. Herein, we report an upcycled gold/graphene monolithic scaffold for the electrocatalytic removal of mercapto pollutants using a recovery-utilization strategy. Reduced graphene oxide (rGO) acts as a conductive scaffold that selectively and near-completely captures gold ions through a reductive adsorption mechanism, forming in situ dispersed metallic gold on its surface. The obtained Au-rGO directly functions as an efficient electrocatalyst for mercapto pollutant degradation, achieving removal efficiencies of 96.07%, 85.81%, and 82.47% for 2-mercaptobenzimidazole, sodium thiophenolate and 2-naphthalenethiol, respectively. Mechanistic study reveals a gold-thiol affinity-driven, adsorption-mediated electrocatalytic degradation pathway, where mercapto pollutants undergo successive adsorption on gold surface, Au-S bond cleavage and indirect oxidative degradation by reactive oxygen species, leading to efficient degradation and mineralization of the mercapto pollutants. We further demonstrate Au-rGO catalyst prepared from practical e-waste, the upcycled catalyst exhibits similar high degradation performance to these pollutants. This work establishes an efficient route for coupling gold recovery with direct catalytic upcycling toward sustainable urban mining and efficient wastewater treatment.
原文链接
分享
引用
