Copper–Nickel Nitride Nanosheets as Efficient Bifunctional Catalysts for Hydrazine‐Assisted Electrolytic Hydrogen Production

Abstract

Electrocatalytic water splitting is one of the sustainable and promising strategies to generate hydrogen fuel but still remains a great challenge because of the sluggish anodic oxygen evolution reaction (OER). A very effective approach to dramatically decrease the input cell voltage of water electrolysis is to replace the anodic OER with hydrazine oxidation reaction (HzOR) due to its lower thermodynamic oxidation potential. Therefore, developing the low-cost and efficient HzOR catalysts, coupled with the cathodic hydrogen evolution reaction (HER) is tremendously important for energysaving electrolytic hydrogen production. Herein, a new-type copper-nickel nitride (Cu 1 Ni 2 -N) with rich Cu 4 N/Ni 3 N interface is rationally constructed on the carbon fiber cloth. The three-dimensional electrode exhibits extraordinary HER performance with an overpotential of 71.4 mV at 10 mA cm -2 in 1.0 M KOH, simultaneously delivering an ultralow potential of 0.5 mV at 10 mA cm -2 for HzOR in 1.0 M KOH/0.5 M hydrazine electrolyte. Moreover, the electrolytic cell utilizing the synthesized Cu 1 Ni 2 -N electrode as both the cathode and anode displays a cell voltage of 0.24 V at 10 mA cm -2 with an excellent stability over 75 h. The present work develops the promising copper-nickel-based nitride as a bifunctional electrocatalyst through hydrazine-assistance for energy-saving electrolytic hydrogen production.

Manipulating dehydrogenation kinetics through dual-doping Co3N electrode enables highly efficient hydrazine oxidation assisting self-powered H2 production

“…2d) spectra can be fitted into W-N (33.3 and 34.8 eV) and P-Co bonds (129.1 eV) 37 , respectively, besides the peaks at 35.6, 37.5, and 133.4 eV originated from the surface oxidation 37,38 . These XPS results suggest that the doping of P and W could induce the charge redistribution, and doping could drive the interfacial charge transfer from doped P/W and Co to N, which leads to the peak shift of Co and N 8,10,39 . In order to further confirm this phenomenon, the synchrotron-based X-ray absorption near edge structure (XANES) Co L-edge and N K-edge spectra for PW-Co 3 N NWA/NF and Co 3 N NWA/N are further collected, as shown in Fig.…”

“…Thus, it is one of the central task to exploit green and efficient approaches to produce H 2 , among which electrocatalytic water splitting is deemed as the suitable technique 5,6 . However, the key challenge originates from the intrinsically sluggish kinetics of anodic oxygen evolution reaction (OER, 4OH − →O 2 + 2H 2 O + 4e − , 1.23 V vs. RHE) involving four-electron-transfer process 7 , which not only lead to the energy wastage, but also further increase the cost due to the utilization of noble metal based electrocatalysts, thus highly limits the large-scale application 8 . Hence, it is greatly desired to develop alternative strategy different from fabricating high performance OER electrocatalysts in order to avoid the high energy consumption at the anode.…”

Boron‐Induced Electronic‐Structure Reformation of CoP Nanoparticles Drives Enhanced pH‐Universal Hydrogen Evolution

“…[1] Currently,Ptbased catalysts are still the pioneering ones in catalyzing the hydrogen evolution reaction (HER), capable of working with greater efficiency irrespective of pH value; [2] however,t heir commercial applications are largely restricted by the highcost, scarce-reserve and unsatisfactory stability. [3] Seeking transition-metal-based electrocatalysts with cost-effective, earth-abundant, high-efficiency,a nd good durability thus is of significance to expedite global scalability of hydrogen energy applications. [4] To date,t ransition-metal for example, phosphides, [5] sulfides, [6] selenides, [7] nitrides, [3c, 8] borides, [9] and others, [10] have been explored to replace the Pt-based catalysts.A mong them, transition-metal phosphides (TMPs) have drawn attention, owing to the advantages they offer in terms of electrical conductivity,m echanical strength, chemical tolerance,and low cost.…”

Rh2S3/N‐Doped Carbon Hybrids as pH‐Universal Bifunctional Electrocatalysts for Energy‐Saving Hydrogen Evolution

“…Herein, carbon support was used as the standard, and C s is 1.57 mF cm −2 according literature. [20] ECSA was calculated as follows: . [20,74,75] The EIS measurements were performed at open-circuit potential in the frequency range from 0.1 Hz to 100 KHz with an alternating current voltage amplitude of 5 mV.…”

“…Of note, Rh 2 S 3 /NC could be adopted into diverse pH solution, furtherly broadening its usage scenarios and shrinking the usage cost. And compared with other electrocatalysts applied in the hydrazine-assist hydrogen generation system, [19][20][21][22][23] the Rh 2 S 3 /NC electrode could effectively produce hydrogen in the solution with less concentration of hydrazine, achieving higher economic benefits. For deeply understanding its excellent performance, theoretical calculations have been performed and confirm that Rh sites in Rh 2 S 3 can easier conduct the adsorption and desorption of the H atom, and the dehydrogenation of adsorbed NHNH, resulting in the excellent catalytic performance.…”