Efficient upcycling electroplating sludge and waste PET into Ni-MOF nanocrystals for the effective photoreduction of CO2

Upcycling the electroplating sludge (EPS) and PET waste into metal-organic-frameworks (MOFs) is beneficial for both pollution mitigation and sustainable economy. Herein, we report a green synthesis of Ni-MOF nanocrystals by simultaneously using EPS and PET waste as precursors without any precedent. In particular, when EPS was fully utilized, with numerous Fe3+/Cu2+ ions coexisting with Ni2+ ions, the desired Ni-MOFs could still be successfully fabricated. The Ni-MOF nanocatalysts exhibited an excellent activity towards the photoreduction of CO2, giving 9.68 x 10(3) mu mol h(-1) g(-1) of CO with 96.7% selectivity over H-2 evolution. Additionally, the apparent quantum yield at 420 nm is 1.36%, which is superior to that of most catalysts in similar systems. This study clearly suggests that the MOF nanocrystals with excellent photocatalytic performances could be successfully fabricated from solid wastes.

Automated summary

This study demonstrates a green synthesis method of Ni-MOF nanocrystals using electroplating sludge and PET waste as precursors, showing excellent photocatalytic performance for the photoreduction of CO2. The Ni-MOF nanocatalysts exhibited high activity and selectivity, with an apparent quantum yield superior to most catalysts in similar systems.