Constructing fecal-derived electrocatalysts for CO₂ upcycling: simultaneously tackling waste and carbon emissions

The escalating global fecal waste and rising CO₂ levels present dual significant environmental challenges, further intensified by urbanization. Traditional fecal waste management methods are insufficient, particularly in addressing the related health risks and environmental threats. This study explores the synthesis of biochar from pig manure as a carbon substrate to disperse and stabilize Cu nanoparticles, resulting in the formation of an efficient Cu-NB-2000 electrocatalyst for electrocatalytic CO₂ reduction (ECR). Through characterization analyses and electrolysis tests, the structure-activity relationships were evaluated, revealing enhanced catalytic activity and selectivity towards value-added multicarbon products. At an optimal potential, the catalyst achieved a remarkable faradaic efficiency for ECR (87.14%) and multicarbon products (44.80%), outperforming previously reported biochar-supported Cu catalysts. The high selectivity was attributed to the substantial presence of pyridine N and the distinctive Cu-N coordination structure. This work introduces, for the first time, a method for preparing an ECR catalyst by loading Cu nanoparticles onto biochar derived from pig manure. This approach not only promotes the valorization of organic waste but also efficiently converts CO₂, offering an effective strategy for an integrated "pollution reduction-carbon mitigation" management system.