Interfacial engineering and hydrophilic/aerophobic tuning of Sn4P3/Co2P heterojunction nanoarrays for high-efficiency fully reversible water electrolysis

The simultaneous integration of electronic regulation and architectural engineering in one electrocatalyst represents a powerful leverage to concurrently boost the electrocatalytic performance towards overall water splitting. We herein rationally fabricate Sn4P(3)/Co2P stalk - cap -typed nanoarrays (Sn4P(3)/Co2P SCNAs) with abundant heterointerfaces and elaborately implanted caps . The nanoarrayed structure can substantially enlarge the exposure of active sites and promote the mass/electron transport, thus accelerating the reaction kinetics. Moreover, the purposely grafted caps are beneficial to increase the hydrophilicity/aerophobicity, which facilitate the water affinity and release of generated gas bubbles. Accordingly, the obtained Sn4P3/Co2P SCNAs deliver exceptional electrocatalytic performances towards the HER and OER, as reflected by the over potentials of 45.4 and 280.4 mV at 10 mA cm(-2), respectively. More impressively, the two-electrode electrolyzer assembled by freestanding Sn4P(3)/Co2P SCNAs requires a cell voltage of 1.56 V at 10 mA cm(-2) and exhibits superior stability and full reversibility, holding great potential in practical water electrolysis.

Automated summary

The simultaneous integration of electronic regulation and architectural engineering in one electrocatalyst provides a powerful leverage to enhance the electrocatalytic performance for water splitting. A novel nanoarray structure with abundant heterointerfaces and well-designed caps is fabricated, which greatly increases the exposure of active sites and promotes mass/electron transport. Moreover, the grafted caps improve the hydrophilicity/aerophobicity, facilitating water affinity and gas bubble release. The obtained Sn4P3/Co2P SCNAs exhibit exceptional electrocatalytic performances for the HER and OER, as well as excellent stability and reversibility in practical water electrolysis, showing great potential for practical applications.