Pt embedded Ni3Se2@NiOOH core-shell dendrite-like nanoarrays on nickel as bifunctional electrocatalysts for overall water splitting

Abstract

Developing high-performance bifunctional catalysts toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential to enhance water splitting efficiency for large-scale hydrogen production. Neither noble metal Pt nor transition metal compounds show satisfactory performances for both HER and OER simultaneously. Here, we prepared a three-dimensional Pt-Ni 3 Se 2 @ NiOOH/NF (PNOF) hybrid catalyst via in-situ growth strategy. Benefitting from the self-supported structure and oxygen vacancies on the surface of NiOOH nanosheets, the PNOF electrode shows remarkably catalytic performance for dual HER and OER. The overall water electrolyzer using PNOF as anode and cathode can achieve a current density of 10 mA cm −2 at a low voltage of 1.52 V with excellent long-term stability, which is superior to precious metal catalysts of Pt/C and Ir/C. This study provides a promising strategy for preparing bifunctional catalysts with high performance.

Hierarchical iridium-based multimetallic alloy with double-core-shell architecture for efficient overall water splitting

“…The Pt/C and IrNiCu HCSA exhibit the smallest resistance, possessing a lower charge-transfer resistance and faster charge transfer rate [19]. CV curves under different scanning rates (5,10,20,40,60, 80 and 100 mV s ) in the voltage range of 0.9-1.0 V (vs. RHE) were performed as shown in Figs S11-S15. Under the same voltage, the current density of the IrNiCu HCSA is the maximum value.…”

“…Chronopotentiometry was employed to evaluate the stability of the as-prepared catalysts at a constant current density of 10 mA cm −2 . To estimate the electrochemical active surface areas (ECSAs), the electrochemical double-layer capacitance (C dl ) was determined by CVs tested at different scan rates (5,10,20,40,60,80, and 100 mV s −1 ) in the potential windows of 0.9 to 1.0 V versus RHE [46]. For the overall water splitting, a two-electrode system with 0.5 mol L −1 H 2 SO 4 solution was used, and two carbon papers with a size of 1 cm × 1 cm were used as the cathode and anode for HER and OER, respectively.…”

“…Alloying Ir with transition group metals [19,[24][25][26][27][28][29][30][31][32][33][34] is generally regarded as an effective strategy that not only substantially reduces the usage of Ir but also facilitates the catalytic activity and stability for water splitting by tuning the d-band structure and oxygen adsorption energy on the surface of Ir. Another strategy to optimize the overall catalytic activity is to tune the geometric shape of the nanocatalysts [18,[35][36][37][38][39][40][41][42]. A hierarchical alloy architecture is believed to show the capability of promoting the initial activity with more active surface area exposed to reactants [43].…”

3D ordered mesoporous cobalt ferrite phosphides for overall water splitting

“…Therefore, extensive studies have been performed to construct economical and earth-abundant catalysts as alternative candidates toward high-efficiency water electrolysis. Transition metal (Co, Ni, Fe, Mn) oxides [8], sulfides [9][10][11], phosphides [12,13], selenides [14,15], and perovskites [16] have been exploited as electrocatalysts for water electrolysis and impressive progress has been achieved. Particularly, transition metal phosphides attract more attention attributed to their low cost, natural abundance, and superior catalytic performance [17][18][19][20][21].…”

Ni@RuM (M=Ni or Co) core@shell nanocrystals with high mass activity for overall water-splitting catalysis

“…Electrochemical water splitting is considered as the key technology to provide high-purity hydrogen for the nextgeneration of sustainable global energy system [1][2][3]. The key to the development of this technique is the exploitation of effective catalysts to improve the slow kinetics of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), thus maximizing the utilization efficiency of electricity [4][5][6][7]. Although some progress has been made in respect of non-noble metal catalysts, Pt/C and RuO 2 /IrO 2 still outperform most of the reported catalysts for HER and OER, respectively [8][9][10][11][12][13][14].…”