The OER/ORR activities of copper oxyhydroxide series electrocatalysts

Copper oxyhydroxide (CuOOH), an unavoidable oxidic product of CuO and Cu(OH)2 electrocatalysts, is always ignored in water splitting. In this work, we investigated the OER /ORR electrocatalytic activity of all CuOOH series (C2/m, Cmc21, and Pmn21) and proposed an improvement scheme for catalytic activity using the DFT method. The results showed that pure CuOOH matrixes with large OER/ORR overpotentials (eta OER/ORR) were inert toward OER/ORR. Therefore, eleven metals (Mn, Fe, Co, Ni, Zn, Mo, Ru, Rh, Pd, W, and Ir) were used to activate the CuOOH substrates. It is found that the OER/ORR performances of all CuOOH series can be significantly improved by Co or Rh doping. Especially for 2D-layered C2/m-CuOOH substrate, the eta OER/ORR was reduced from 1.26 V/2.01 V to 0.25 V/0.22 V and 0.36 V/0.46 V by Co and Rh embedding, respectively, which mainly owes to the regulation from the moderate d-orbital electrons of doped Co and Rh. This work systematically revealed the OER/ORR performance of the CuOOH series, which will promote the development of new catalysts and help us to deeply understand and improve the OER/ORR performance of previous copper oxide electrocatalysts.