Rh single atoms/clusters confined in metal sulfide/oxide nanotubes as advanced multifunctional catalysts for green and energy-saving hydrogen productions.

In this work, smart strategies are conducted to design advanced multifunctional electrocatalysts: Co 3 S 4 /CoO x heterostructured nanosheets-assembled nanotube arrays on 3D framework integrated with single Rh atoms and subnanometer clusters. The catalyst can reach current density of 10 mA cm−2 at low overpotentials of 248.2, and 56.1 mV for oxygen evolution reaction, and hydrogen evolution reaction, respectively. The catalyst also shows very low potential of 1.32 V for urea oxidation reaction at 10 mA cm−2. A water electrolyzer that achieves current density of 10 mA cm−2 at small cell voltage of 1.45 V is prepared under action of the developed catalyst. We also conduct urea electrolysis assembled with the catalyst and find that the device requires a cell voltage of only 1.35 V to drive a current density of 10 mA cm−2, proving the great potential of our catalyst for simultaneous energy-saving H 2 production and the treatment of urea-rich wastewater. [Display omitted] • Constructing Rh-Co 3 S 4 /CoO x heterostructures for overall water and urea electrolysis. • Single Rh atoms and clusters play as promising adjutant for the host Co 3 S 4 /CoO x. • The developed Rh-Co 3 S 4 /CoO x shows extraordinary HER, OER, and UOR performance. • The overall water and urea electrolysis show excellent performance under action of the Rh-Co 3 S 4 /CoO x electrode. [ABSTRACT FROM AUTHOR]