Constructing Multiple Heterostructures on Nickel Oxide Using Rare‐earth Oxide and Nickel as Efficient Bifunctional Electrocatalysts for Overall Water Splitting

Abstract

Constructing heterostructured electrocatalyst is a promising strategy to explore inexpensive and effective catalysts towards oxygen evolution reaction (OER), hydrogen evolution reaction (HER) and the overall water splitting (OWS). Here, amorphous NiO 2D layers decorated with Ni and rare earth oxide (REO x ) nanoparticles, which possess multiple heterostructures (NiÀ NiO and REO x -NiO), have been synthesized by the sequential electrodeposition on carbon cloth. The electrocatalytic performances for the prepared Er 2 O 3 /NiÀ NiO and CeO 2 /NiÀ NiO have been evaluated, exhibiting improved HER (39 mV@10 mA cm À 2 ) and OER (318 mV@50 mA cm À 2 ) activities in contrast to the single component, respectively. Additionally, the two-electrode system (Er 2 O 3 /NiÀ NiO//CeO 2 /NiÀ NiO) presents an excellent OWS property which displays a low potential of 1.58 V to reach 10 mA cm À 2 . This work helps to deepen the understanding of the synergetic interaction between dissimilar materials in heterostructured catalyst, and provides guidance for the further exploration and evolution of nanomaterials in green energy conversion technology.

Homogenous Cr and C Doped 3D Self-Supporting NiO Cellular Nanospheres for Hydrogen Evolution Reaction

“…At the same current density of 10 mA·cm −2 , the overpotentials of NiO-C/NF, NiO-Cr-C/NF-1 and NiO-Cr-C/NF-2 are 205 mV, 113 mV and 92 mV, respectively. The performance of the CoP-NiO-Cr-C/NF-3 catalyst is inferior to noble metal electrocatalysts [ 50 , 51 , 52 , 53 ]; however, it is superior to the most reported NiO-based electrocatalysts [ 22 , 54 , 55 , 56 , 57 ] ( Table 1 ). NiO-Cr-C/NF-3 and 10% Pt/C/NF reach a current density of 208 mA·cm −2 and 191 mA·cm −2 , respectively, when the overpotential is 400 mV.…”

Heterostructure Engineering of 2D Superlattice Materials for Electrocatalysis

“…iv) Metal nanoclusters modification: Metal nanoclusters have been proven to act the role of functional groups to effectively adjust the surface charge of 2D materials in an aqueous solution. [200] Sun et al manipulated the surface electronic properties of 2D C 3 N 4 through the loading of a small amount of Co clusters on to the 2D nanosheets (<5 wt%) (Figure 7E). Due to the different electronegative properties, the N atoms in the 2D C 3 N 4 are chemically affinitive with the Co nanoclusters to form a 2D Co-C 3 N 4 nanostructure, which can tune the negatively charged C 3 N 4 surfaces into positively charged Co-C 3 N 4 surfaces.…”

“… iv) Metal nanoclusters modification : Metal nanoclusters have been proven to act the role of functional groups to effectively adjust the surface charge of 2D materials in an aqueous solution. [ 200 ] Sun et al. manipulated the surface electronic properties of 2D C 3 N 4 through the loading of a small amount of Co clusters on to the 2D nanosheets (<5 wt%) (Figure 7E).…”

Hydrothermally Fabricated NiO@TiO2–Nanofiber Composite for Efficient Electrocatalytic Hydrogen Evolution Reaction

“…TM-based nanomaterials (Fe, Co, Ti, Cu, and Ni) have been studied extensively as catalysts for HER. Among them, nickel-based electrocatalysts, particularly nickel oxide, have attracted considerable attention for HER electrocatalytic application due to their high abundance, low cost, high corrosion resistance, storage capacity, and remarkable electrochemical capabilities. ,− Besides nickel, titanium oxide-based nanomaterials have also been heavily investigated as electrocatalysts. Especially, TiO 2 -based nanomaterials that are decorated with other catalytically active metals prepared by hydrothermal treatment methods directly on Ti substrates have been highly investigated …”