Shilong Liu

Bio: Shilong Liu is an academic researcher from Guangdong Pharmaceutical University. The author has contributed to research in topics: Oxygen evolution & Overpotential. The author has an hindex of 1, co-authored 4 publications receiving 5 citations. Previous affiliations of Shilong Liu include Guangzhou Higher Education Mega Center.

Cobalt phosphide supported by two-dimensional molybdenum carbide (MXene) for the hydrogen evolution reaction, oxygen evolution reaction, and overall water splitting

Abstract: Developing a low cost, high performance, and durable bifunctional catalyst to boost the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) for water splitting is a critical yet challenging task. Transition metal phosphides have been identified as promising dual functional catalysts recently. Herein, we report a facile strategy to construct a heterostructure catalyst by integrating cobalt phosphide with molybdenum carbide (MXene). The CoP/Mo2CTx (T is the surface terminal group) catalyst exhibited good HER activity with an overpotential of 78 mV at a current density of 10 mA cm−2, close to that of the Pt/C benchmark, and its OER performance is markedly better than that of the RuO2 benchmark, evidenced by a very small overpotential of 260 mV at 10 mA cm−2 in 1 M KOH. Impressively, when employed for overall water splitting, CoP/Mo2CTx also outperformed the Pt/C + RuO2 combination with a voltage of 1.56 V @ 10 mA cm−2. Density functional theory (DFT) calculations revealed that CoP/Mo2CTx has appropriate water adsorption especially the optimal H* adsorption free energy (ΔGH*), and the Mo2C MXene support can significantly increase the total density of states and downshift the d-band center for the HER, while for the OER, multiple characterization techniques of CoP/Mo2CTx post the OER test show that CoP in the catalyst can be transformed into Co–OOH during the electrocatalytic process. This study can provide a pathway for the design and fabrication of MXene-supported noble-metal-free bifunctional catalysts toward practical water splitting and energy conversion.

Heterostructure and Oxygen Vacancies Promote NiFe 2 O 4 /Ni 3 S 4 toward Oxygen Evolution Reaction and Zn-Air Batteries

Abstract: Developing high-performance catalysts for oxygen evolution reaction (OER) is critical for the widespread applications of clean and sustainable energy through electrochemical devices such as zinc-air batteries and (photo)electrochemical water splitting. Constructing heterostructure and oxygen vacancies have demonstrated great promises to boost the OER performance. Herein, we report a facile strategy to fabricate hetero-structured NiFe2 O4 /Ni3 S4 nanorods, where NiFe2 O4 can be derived from Fe-based metal-organic frameworks (MOFs). The NiFe2 O4 /Ni3 S4 catalyst exhibited excellent OER performance, evidenced by an overpotential value of 357 mV at the current density of 20 mA cm-2 , and a small Tafel slope of 87.46 mV dec-1 in 1 M KOH, superior to the benchmark IrO2 catalyst. Moreover, NiFe2 O4 /Ni3 S4 outperformed with regard to long-term durability for OER than IrO2 . Such outstanding OER performance is mainly accounted by the interface between NiFe2 O4 and Ni3 S4 , and the presence of rich oxygen vacancies. When employed as air-cathode in zinc-air batteries, the NiFe2 O4 /Ni3 S4 decorated battery had a high round-trip efficiency of 62.1% at 10 h, and possessed long-term stability of >50 h. This study may pave the way for fabricating non-noble-metal-based cost-effective, efficient and durable electrocatalysts for OER, zinc-air batteries, and beyond.