TY - JOUR AU - Wang, Xiaoyang AU - He, Yu AU - Han, Xiaopeng AU - Zhao, Jun AU - Li, Lanlan AU - Zhang, Jinfeng AU - Zhong, Cheng AU - Deng, Yida AU - Hu, Wenbin PY - 2022 TI - Engineering cobalt sulfide/oxide heterostructure with atomically mixed interfaces for synergistic electrocatalytic water splitting JO - Nano Research SN - 1998-0124 SP - 1246 EP - 1253 VL - 15 IS - 2 AB - It remains challenging to develop economical and bifunctional electrocatalysts toward oxygen/hydrogen evolution reactions (OER/HER). Herein, we construct Co9S8 nanoflakes decorated Co3O4 nanoarrays with enriched heterogeneous interface zones on Ni foam (Co9S8@Co3O4/NF) via a novel step-wise approach. The Co9S8@Co3O4/NF hybrid manifests excellent performance with low overpotentials of 130 mV for HER (10 mA·cm–2) and 331 mV for OER (100 mA·cm–2), delivering a small voltage of 1.52 V for water splitting at 10 mA·cm–2 as well as outstanding catalytic durability, which surpasses precious metals and previously reported earth-abundant nanocatalysts. Further experimental and theoretical investigations demonstrate that the excellent performance is attributed to the followings: (ⅰ) Highly conductive Ni facilitates the efficient charge transfer; (ⅱ) porous core-shell nanoarchitecture benefits the infiltration and transportation of gases/ions; (ⅲ) heterogeneous interface zones synergistically lower the chemisorption energy of hydrogen/oxygen intermediates. This work will shed light on the controllable synthesis and engineering of heterostructure nanomaterials for clean energy storage and conversion technologies. UR - https://doi.org/10.1007/s12274-021-3632-4 DO - 10.1007/s12274-021-3632-4