Nanoporous Microspheres of Co-Zn-S as Catalysts for Oxygen Evolution by Water Splitting and Hydrogen Generation by Ammonia Borane Hydrolysis

Abstract

The nanoporous microspheres of Co-Zn-S were synthesized by a solvothermal method. The as-obtained Co-Zn-S microspheres, as a non-noble metal catalyst, exhibited highly electrocatalytic activity for oxygen evolution reaction (OER) in alkaline electrolyte. It showed a low overpotential of only 320 mV to afford a current density of 10 mA cm−2 and a Tafel slope of 80.43 mV dec−1. Furthermore, the nanoporous microspheres of Co-Zn-S retained excellent electrocatalytic stability within a period of 36000 s. The catalyst also showed good catalytic performance toward the hydrolysis of ammonia borane to produce around 70 mL of H2 within the time of 30 minutes at room temperature. The nanoporous microspheres of Co-Zn-S exhibits the potential applications for hydrogen/oxygen production by water splitting or ammonia borane hydrolysis.

Hydrangea‐like ZnS/ZnIn 2 S 4 microspheres with outstanding photocatalytic degradation of xylenol orange and thymol blue under vis irradiation

“…In Figure 5(a), the elements of Zn, In and S are found in the overall XPS spectrum, indicating that these elements are present in the material. For Zn 2p in Figure 5(b), the doublet peaks of Zn 2p 1/2 and Zn 2p 3/2 , respectively, positioned at 1045.3 and 1022.1 eV correspond to the valence state of Zn II [22,23]. The In 3d XPS spectrum in Figure 5(c) shows that the In 3d 2/3 and In 3d 5/2 peaks are located at 452.7 and 445.2 eV, respectively, which can be ascribed to In III [24].…”

Carbon dots-confined CoP-CoO nanoheterostructure with strong interfacial synergy triggered the robust hydrogen evolution from ammonia borane

“…However, the current best catalysts contain Pt or Ru [9][10][11], the high cost and limited reserves of which greatly inhibit large-scale use. Therefore, the development of highly active and stable non-noble-metal catalysts, including oxides [12,13], sulfides [14], carbides [15] and phosphides [16,17], is crucial to AB becoming a widely used storage material. Transition-metal phosphides can efficiently catalyse hydrogen evolution, owing to their similarity to hydrogenase [18,19], but are limited by low reactivity and poor cyclic stability.…”

Improved catalytic effect and metal nanoparticle stability using graphene oxide surface coating and reduced graphene oxide for hydrogen generation from ammonia–borane dehydrogenation

“…For the most part, Pt, [8][9][10][11][12] Ru, [13][14][15] and Pd 16 based catalysts outshine non-noble metals, such as Ni, Cr, 17 Co, [18][19][20] RuPd@GO, 21 Ag/Pd, 22,23 Fe, 24,25 Ag-Ni based nanoparticles, 26 Au-Pd, 27 mesoporous carbon nitride supported Pd and Pd-Ni NPs, 28 PdNi-CeO 2 , 29 NiPt NPs with supported CeO 2 30 (efficient hydrogen generation from an alkaline solution of hydrazine), N-doped graphene supported Co-CeOx, 31 and transition metal nanoparticles with GO 32 for hydrogen generation under the above conditions. Though there has been development in the catalytic efficiencies of bimetallic catalysts, for example, Co-Pd 33,34 and core-shell species such as Au@Co, 35 and monometallic catalysts, the general utilization of these noble metals is restricted by their high cost and the extraordinary amount required.…”