Nickel Diselenide Ultrathin Nanowires Decorated with Amorphous Nickel Oxide Nanoparticles for Enhanced Water Splitting Electrocatalysis

Abstract

Well-designed hybrid materials based on noble metal-free elements have great potential to generate hydrogen (H ) and oxygen (O ) sustainably via overall water splitting for developing practical energy-related technologies. Herein, an accessible method is presented to synthesize nickel diselenide (NiSe ) ultrathin nanowires decorated with amorphous nickel oxide nanoparticles (NiO NPs) as multifunctional electrocatalysts (NSWANs) for hydrogen and oxygen evolution reaction (HER and OER). The NSWANs exhibit quite low HER and OER overpotentials of 174 and 295 mV, respectively, holding the current density of 20 mA cm for 24 h continuous operations in alkaline media. Meanwhile, a cell voltage of 1.547 V at the current density of 10 mA cm for overall water splitting has been achieved by the NSWANs for the practical application, which could maintain fascinating activity of 20 mA cm for 72 h without degradation. The decorated NiO NPs not only prevent the NiSe from further oxidation but also expose requisite active sites for electrocatalytic process. It is believed that this study may provide a valuable strategy to design high-efficiency electrocatalysts and expand the applications of selenide-based materials.

Highly Active Ternary Nickel–Iron oxide as Bifunctional Catalyst for Electrochemical Water Splitting

“…Thus the development of sufficiently available, low‐cost, highly active OER and/or HER electrocatalyst in alkaline medium is of high demand in the present scenario. Recently, nickel–based electrocatalysts such as oxides, hydroxides, chalcogenides, phosphides, nitrides etc. have exhibited very promising electrocatalytic performance and durability towards OER and/or HER .…”

Synthesis of Sub‐2 nm Iron‐Doped NiSe2 Nanowires and Their Surface‐Confined Oxidation for Oxygen Evolution Catalysis

“…Although examples have been demonstrated for making ultrathin nanostructures,s uch as metals (e.g.A u, [3] Pt, [4] Cu [5] ), oxides (e.g. [12] Thenucleation and growth of these nanocrystals commonly happen at high reaction temperature,m aking it hard to maintain the ultrathin nature because of the high surface energy,w hich leads to irregular structures. [12] Thenucleation and growth of these nanocrystals commonly happen at high reaction temperature,m aking it hard to maintain the ultrathin nature because of the high surface energy,w hich leads to irregular structures.…”

“…TiO 2 , [6] W 18 O 49 [7] ), sulfides (e.g.B i 2 S 3 , [8] Sb 2 S 3 , [8b] ZnS [8b, 9] ), and rare earth compounds (e.g.E uOH, [10] GdOOH [11] ), reports are still rare,p articularly for transitionmetal chalcogenides (TMCs). [12] Thenucleation and growth of these nanocrystals commonly happen at high reaction temperature,m aking it hard to maintain the ultrathin nature because of the high surface energy,w hich leads to irregular structures. [13] Furthermore,appropriate surfactants with optimum binding strength and small steric bulk that template the 1D growth are crucial to synthesizing UNWs.…”

α‐Ni(OH)2 Originated from Electro‐Oxidation of NiSe2 Supported by Carbon Nanoarray on Carbon Cloth for Efficient Water Oxidation

“…The corresponding FT of EXAFS spectra of stage I provided the radial distribution of neighboring atoms around the Ni atom. As shown in Figure b, the FT spectra of NiSe 2 presented a single peak around 2.15 Å at the initial state, which belonged to Ni–Ni bonds in NiSe 2 . Afterward, the peak intensity from Ni–Ni bonds of NiSe 2 was decreased gradually, and a new peak originating from Ni–O bonds emerged at ≈1.52 Å, which could be assigned to the Ni–O bonds in nickel hydroxide, implying that NiSe 2 transformed to Ni(OH) 2 gradually at stage I.…”

“…Although the state‐of‐art noble metal‐based materials such as IrO 2 and RuO 2 show outstanding activity toward OER, their wide applications are highly restricted by their low abundance and high cost . In recent years, tremendous research efforts have been devoted to developing earth‐abundant, low‐cost, and highly‐efficient OER electrocatalysts, among which transition metal based compounds including transition metal oxides, hydroxides, phosphides, sulfides, and selenides have been demonstrated to have favorable electrocatalytic property and durability. Meanwhile, to further enhance the activity of these electrocatalysts, two common approaches including morphology control and composition modification have been adopted to either increase the number of active sites or optimize their intrinsic activities .…”