Efficient Electrocatalytic Oxygen Evolution at Extremely High Current Density over 3D Ultrasmall Zero‐Valent Iron‐Coupled Nickel Sulfide Nanosheets

Abstract

Nonprecious water oxidation electrocatalysts that perform well at high current densities are among the key enabling drivers of renewable energy technologies. Herein, we report a novel strategy to produce 3D ultrasmall zero‐valent iron‐coupled nickel sulfides nanosheets (Fe0−NixSy) hybrid on self‐supported conductive Ni foam (denoted as Fe0−NixSy/NF) through a robust single‐step gas–solid reaction. In this 3D hybrid, the Fe0−NixSy nanosheets with a length of approximately 400 nm and an average thickness of 33 nm are uniformly grown on the Ni foam. Benefiting from the unique 3D hierarchical structure and synergistic effect between Fe0 and NixSy, the 3D Fe0−NixSy/NF hybrid shows an excellent electrocatalytic activity towards oxygen evolution reaction (OER) at extremely high current densities in basic media. The current densities of 1000 and 1500 mA cm−2 are achieved at low potentials of 1.57 and 1.60 V, respectively, thus meeting the expected OER standards for industrial applications. These overpotentials of the 3D Fe0−NixSy/NF hybrid are the lowest among all previously reported nickel‐sulfide‐based electrocatalysts, and are even superior compared to state‐of‐the‐art Ir/C catalysts. We further demonstrate that the integration of the 3D Fe0−NixSy/NF electrocatalyst as both anode and cathode with a silicon photovoltaic cell enables highly active and sustainable solar‐driven overall water splitting.

Ultrathin tin monosulfide nanosheets with the exposed (001) plane for efficient electrocatalytic conversion of CO2 into formate

“…Inspired by the excellent CO 2 RR activity, a two-electrode electrolyzer was further assembled with the ultrathin SnS NS cathode for the CO 2 RR and an Ir/C anode for the oxygen evolution reaction (OER). [45][46][47][48][49][50][51][52] As shown in Fig. S12a, † the polarization curve of the CO 2 RR-OER cell displayed electrocatalytic properties, in which the current density could reach 6.54 mA cm À2 at 3.0 V. Notably, the current density was slightly decreased by only 10% aer 10 hours of continuous reaction (inset of Fig.…”

Ultrathinning Nickel Sulfide with Modulated Electron Density for Efficient Water Splitting

“…[37,[62][63][64][65][66] Meanwhile, the deconvolution peaks of the highresolution O 1s spectrum located at 531.3 and 531.9 eV, which were usually attributed to the adsorbed water and metal-oxygen bonds, respectively, suggesting the formation of Ni-Fe(oxy) hydroxide on the surface of Fe 0.9 Ni 2.1 S 2 electrode during the OER process (Figure 4f). [67] The S 2p XPS spectra showed that the signal strength of element S on the surface of Fe 0.9 Ni 2.1 S 2 decreased OER cycling test while the peak intensity of oxidized S increased ( Figure S22, Supporting Information). [66] Note that the formed surface (oxy)hydroxide layer would gradually achieve a stable state and avoid a further oxidation of the catalyst core, forming an interface between the incipient catalyst and the fresh Ni-Fe (oxy)hydroxides.…”

Integrated System of Solar Cells with Hierarchical NiCo2O4 Battery-Supercapacitor Hybrid Devices for Self-Driving Light-Emitting Diodes

“…Currently, electrochemical energy storage devices cover batteries and supercapacitors primarily [6][7][8][9][10][11][12]. Batteries are really a big family, including conventional lead-acid [13,14], nickel-cadmium [15,16], nickel-metal hydride [17][18][19], and lithium-ion batteries [20][21][22][23][24][25], as well as newly developed batteries such as lithium-sulfur [26][27][28], lithium-air [29][30][31], lithium-CO 2 [32][33][34], sodium/potassium/magnesium/aluminum/zinc ion [35][36][37][38][39][40][41][42][43][44], and aqueous metal ion batteries [45,46].…”