Face mask-derived Ni, N-doped graphene sheets for electrocatalytic CO2-to-CO reduction

The COVID-19 pandemic that is still prevalent around the globe each day consumes massive disposable face masks and consequently lays a heavy burden on waste management. Meanwhile, the incineration of these medical wastes further escalates the already overwhelming carbon emission that leads to global warming and climate change. To offer a potential solution addressing medical waste and CO 2 emission challenges, we herein develop a synthetic protocol to upgrade face masks into Ni, N-doped graphene (Ni–N-C) sheet catalysts for selectively reducing CO 2 into CO electrochemically. The high specific surface area and the uniform dispersion of Ni active sites of the catalyst derived from a regular disposable face mask enable a near-unity CO Faradaic efficiency (FE) at the current density of 200 mA cm −2 . This study offers outside-of-the-box thinking to address environmental issues by turning medical wastes into CO 2 reduction catalysts.