Jingwei Li

Synthesis of 3D-MoO2 microsphere supported MoSe2 as an efficient electrocatalyst for hydrogen evolution reaction

Many efforts have been devoted to the exploration of non-noble-metal electrocatalysts for the hydrogen evolution reaction (HER) in recent years. Here, we have developed a 3D-MoO2 microsphere supported MoSe2 for HER, via a facile hydrothermal approach followed by selenylation treatment. Loosely stacked MoSe2 layers are formed on the conductive MoO2 surface, and act as active sites for HER. Meanwhile, the metallic inner MoO2 facilitates electron transport for proton reduction. In addition, the MoSe2 could protect the inner MoO2 from the acidic electrolyte in the HER precess. Significantly, the as-synthesized MoO2/MoSe2 exhibits excellent catalytic activity for HER, characterised by a low onset potential of -101 mV vs reversible hydrogen electrode, a small overpotential of 167 mV at a current density of 10 mA cm-2, along with Tafel slope values of 68 mV dec-1, as well as outstanding stability in 0.5 mol L-1 H2SO4.Many efforts have been devoted to explore non-noble metal electrocatalysts for hydrogen evolution reaction (HER) in recent years. Here, we developed a 3D-MoO2 microspheres supported MoSe2 via a facile hydrothermal approach followed by selenylation treatment for HER. The loosely stacked MoSe2 layer were formed on the conductive MoO2 surface and acted as active sites for HER. Meanwhile, metallic inner MoO2 facilitates to electron transport for proton reduction. In addition, the MoSe2 could protect the inner MoO2 from the acidic electrolyte in the HER precess. Significantly, the as-synthesized MoO2/MoSe2 exhibits excellent catalytic activity for HER featured by a low onset potential of -101 mV vs reversible hydrogen electrode, a small overpotential of 167 mV at a current density of 10 mA cm-2 along with Tafel slope values of 68 mV dec-1 as well as outstanding stability in 0.5 mol L-1 H2SO4.

Ni3S2 nanowires grown on nickel foam as an efficient bifunctional electrocatalyst for water splitting with greatly practical prospects

It is essential to synthesize low-cost, earth-abundant bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reactions (OER) for water electrolysis. Herein, we present a one-step sulfurization method to fabricate Ni3S2 nanowires directly grown on Ni foam (Ni3S2 NWs/Ni) as such an electrocatalyst. This synthetic strategy has several advantages including facile preparation, low cost and can even be expanded to large-scale preparation for practical applications. The as-synthesized Ni3S2 NWs/Ni exhibits a low overpotential of 81 and 317 mV to render a current density of 10 mA cm-2 for the HER and OER, respectively, in 1.0 mol l-1 KOH solution. The Ni3S2 NWs/Ni was integrated to be the cathode and the anode in the alkaline electrolyzer for overall water splitting with a current density of 10 mA cm-2 afforded at a cell voltage of 1.63 V. More importantly, this electrolyzer maintained its electrocatalytic activity even after continual water splitting for 30 h. Owing to its simple synthesis process, the earth-abundant electrocatalyst and high performance, this versatile Ni3S2 NWs/Ni electrode will become a promising electrocatalyst for water splitting.

Fe 0.2 Ni 0.8 ) 0.96 S tubular spheres supported on Ni foam as an efficient bifunctional electrocatalyst for overall water splitting

Earth-abundant and efficient bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly significant for renewable energy systems. However, the performance of existing electrocatalysts is usually restricted by the low electroic conductivity and the limited amount of exposed active sites. In this work, (Fe0.2Ni0.8)0.96S tubular spheres supported on Ni foam have been prepared by a sulfuration of FeNi layered double hydroxide spheres grown on Ni foam. Benefiting from the unique tubular sphere architecture, the rich inner defects and the enhanced electron interactions between Fe, Ni and S, this electrocatalyst shows low overpotential of 48 mV for HER at 10 mA cm−2 in 1.0 mol L−1 KOH solution, which is one of the lowest value of non-previous electrocatalyts for HER in alkaline electrolyte. Furthermore, assembled this versatile electrode as an alkaline electrolyzer for overall water splitting, a current density of 10 mA cm−2 is achieved at a low cell voltage of 1.56 V, and reach up to 30 mA cm−2 only at an operating cell voltage of 1.65 V.