24 research outputs found
A nanosized CoNi hydroxide@hydroxysulfide core-shell heterostructure for enhanced oxygen evolution
A costâeffective and highly efficient oxygen evolution reaction (OER) electrocatalyst will be significant for the future energy scenario. The emergence of the coreâshell heterostructure has invoked new feasibilities to inspire the full potential of nonâpreciousâmetal candidates. The shells always have a large thickness, affording robust mechanical properties under harsh reaction conditions, which limits the full exposure of active sites with highly intrinsic reactivity and extrinsic physicochemical characters for optimal performance. Herein, a nanosized CoNi hydroxide@hydroxysulfide coreâshell heterostructure is fabricated via an ethanolâmodified surface sulfurization method. Such a synthetic strategy is demonstrated to be effective in controllably fabricating a coreâshell heterostructure with an ultrathin shell (4 nm) and favorable exposure of active sites, resulting in a moderately regulated electronic structure, remarkably facilitated charge transfer, fully exposed active sites, and a strongly coupled heterointerface for energy electrocatalysis. Consequently, the asâobtained hydroxide@hydroxysulfide coreâshell is revealed as a superior OER catalyst, with a small overpotential of 274.0 mV required for 10.0 mA cmâ2, a low Tafel slope of 45.0 mV decâ1, and a favorable longâterm stability in 0.10 M KOH. This work affords fresh concepts and strategies for the design and fabrication of advanced coreâshell heterostructures, and thus opens up new avenues for the targeted development of highâperformance energy materials.Bin Wang, Cheng Tang, HaoâFan Wang, Xiao Chen, Rui Cao, Qiang Zhan