Grave-to-cradle upcycling of Ni from electroplating wastewater to photothermal CO 2 catalysis

Treating hazardous waste Ni from the electroplating industry is mandated world-wide, is exceptionally expensive, and carries a very high CO 2 footprint. Rather than regarding Ni as a disposable waste, the chemicals and petrochemicals industries could instead consider it a huge resource. In the work described herein, we present a strategy for upcycling waste Ni from electroplating wastewater into a photothermal catalyst for converting CO 2 to CO. Specifically, magnetic nanoparticles encapsulated in amine functionalized porous SiO 2 , is demonstrated to efficiently scavenge Ni from electroplating wastewater for utilization in photothermal CO 2 catalysis. The core-shell catalyst architecture produces CO at a rate of 1.9 mol·g Ni −1 ·h −1 (44.1 mmol·g cat −1 ·h −1 ), a selectivity close to 100%, and notable long-term stability. This strategy of upcycling metal waste into functional, catalytic materials offers a multi-pronged approach for clean and renewable energy technologies.