Constructing a bifunctional catalyst with both high entropy alloy nanoparticles and Janus multi-principal alloy nanoparticles for high-performance overall water splitting

Encouraged by the excellent multifunctional catalytic performance of Janus nanoparticles and superior long-term durability of high-entropy alloy nanoparticles, a bifunctional catalyst with high-entropy alloy nanoparticles (HEA-NPs) and Janus multi-principal alloy nanoparticles (JMPA-NPs) is prepared. Beneficial from the accelerated electron/optimized adsorption of intermediate of JMPA-NPs and the nature of high entropy effect of HEA-NPs, the catalyst (HEA/JMPA) exhibits superior OER and HER catalytic performance with excellent stability in 1 M KOH solution. For OER, the overpotential required to reach 20 mA cm−2 (η20) is only 314 mV, which is much better than that of commercial RuO2 catalyst. During the long-term operation at 10 mA cm -2, the potential presents almost no attenuation after 21 h. For HER, the η10 is only 85 mV with superior stability of 108 h. The water electrolyzer which is conducted with HEA/JMPA as both cathode and anode in 1 M KOH (HEA/JMPA (+, -)) exhibits excellent overall water splitting activity. The voltage of HEA/JMPA (+, -) to reach 100 mA cm−2 is only 1.75 V and the current density is as high as 305 mA cm−2 at 1.9 V. The theoretical calculation results also revealed the internal mechanism of the new catalyst on both OER and HER.