Xiaowei Lv

Engineering NiS/Ni2P Heterostructures for Efficient Electrocatalytic Water Splitting

Developing high-active and low-cost bifunctional materials for catalyzing the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) holds a pivotal role in water splitting. Therefore, we present a new strategy to form NiS/Ni2P heterostructures. The as-obtained NiS/Ni2P/carbon cloth (CC) requires overpotentials of 111 mV for the HER and 265 mV for the OER to reach a current density of 20 mA cm-2, outperforming their counterparts such as NiS and Ni2P under the same conditions. Additionally, the NiS/Ni2P/CC electrode requires a 1.67 V cell voltage to deliver 10 mA cm-2 in a two-electrode electrolysis system, which is comparable to the cell using the benchmark Pt/C||RuO2 electrode. Detailed characterizations reveal that strong electronic interactions between NiS and Ni2P, abundant active sites, and smaller charge-transfer resistance contribute to the improved HER and OER activity.

Core-Shell Structured NiCo2O4@FeOOH Nanowire Arrays as Bifunctional Electrocatalysts for Efficient Overall Water Splitting

Exploring earth‐abundant and high‐performance catalysts for water‐splitting is extremely crucial to produce clean hydrogen fuel. In this work, FeOOH was electrodeposited on NiCo2O4 nanowire to form a three dimensional (3D) core‐shell structure on Ni foam (NiCo2O4@FeOOH/NF) as bifunctional catalyst for overall water splitting. To control the thickness of FeOOH shell layer by optimizing electrodeposition time, the NiCo2O4@FeOOH/NF(500s) with FeOOH layer of ∼7 nm thickness exhibits excellent catalytic activity and stability for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution. Moreover, in a two‐electrode water splitting system, extremely small potential of 1.52 V can be achieved for NiCo2O4@FeOOH/NF(500s), giving a current density of 10 mA cm−2. Detailed investigation reveals that the thickness of FeOOH layer, strong electronic interaction at the interface between NiCo2O4 and FeOOH play critical role in the excellent catalytic property.