Molybdenum and Phosphorous Dual Doping in Cobalt Monolayer Interfacial Assembled Cobalt Nanowires for Efficient Overall Water Splitting

Abstract

The necessity for better water splitting requires speedy development of efficient catalysts with high activity, long-term stability, and cost effectiveness. In this work, a bifunctional catalyst originating from the interfacial assembly of a thin Mo,P-codoped Co layer (≈50 nm) shelled Co nanowire (Co-Mo-P/CoNWs) network is fabricated via a facile approach. The catalyst exhibits low overpotentials of 0.08 and 0.27 V to reach a current response of 20 mA cm −2 for the hydrogen evolution reaction and oxygen evolution reaction, respectively, together with long-term stability in 1.0 m KOH medium. The outstanding performance is further demonstrated by a Co-Mo-P/CoNWs-based electrolyzer, which enables a cell voltage of only 1.495 V to reach 10 mA cm −2 , superior to one derived from commercial (Pt/C + RuO 2 /C) as well as to various reports recently published elsewhere. It is recognized that the formation of multiactive centers together with the increased active site number caused by Mo and P dual doping synergistically promote both hydrogen and oxygen evolution performance. Such a hybrid material opens a new approach for developing efficient and cost-effective catalysts for water splitting application.

Highly Effective Freshwater and Seawater Electrolysis Enabled by Atomic Rh‐Modulated Co‐CoO Lateral Heterostructures

“…Embedding heterostructures with a high surface area and excellent-conductive nano-supports under strong interactions and large interfacial contact is another solution. This has been successfully demonstrated by some reports, including the study of Hoa et al [24] on 1D Co metal nanowires (NWs) carrying a Mo, P-doped cobalt layer, the study of Yu et al [25] on 1D Cu NWs carrying NiFe layered double hydroxide nanosheets, and the study of Tran et al [26] on 1D Cu NWs carrying Fe-Ni 2 P/C. Motivated by the above speculation, a novel hybrid coming from rhodium (Rh) heteroatom dispersed cobalt-cobalt oxide (Co-CoO) lateral heterostructure shelling over high-conductive 1D Cu NWs (1D-Cu@Co-CoO/Rh) was developed via a facile process in the present study.…”

“…This suggested that the material suffered an oxidation phenomenon during OER process to form a layer of oxides and hydroxide species that could act as real electroactive sites to accelerate a fast kinetics of such reaction on its surface, as sucessfully demonstrated by electrochemical results as well as by early reports. [24,44] Catalytic performances of materials for HER and OER were also evaluated in a mimic seawater environment with 0.5 m NaCl containing 1.0 m KOH. Figure 5a and Figure S6a, Supporting Information compared HER activities of catalysts by LSV curves, which showed a higher performance of 1D-Cu@ Co-CoO/Rh than 1D-Cu, 1D-Cu@Co-CoO, and Co-CoO/Rh.…”

In Situ Grown Co‐Based Interstitial Compounds: Non‐3d Metal and Non‐Metal Dual Modulation Boosts Alkaline and Acidic Hydrogen Electrocatalysis

“…Based on the core-level N 1s XPS spectra of the two samples, the Co-N, pyridinic-N, and pyrrolic-N of the Co 5.47 N all shifted to lower binding energy in Mo-Co 5.47 N/N-CoO sample, revealing that the electronic structure of the Mo-Co 5.47 N/N-CoO has been modified. The peaks of the Mo 3d XPS spectra such as Mo(III)3d 3/2 , Mo(VI)3d 3/2 , and Mo(0)3d 5/2 conformed with the integration of Mo into other Co-based compounds (Figure 1F), [53,54] but different from those of Mo nitride [55] and other non-nitride Mobased compounds. [56][57][58][59] This indicates that Mo interacted with Co 5.47 N and not CoO, and affirming that the final sample is Mo-Co 5.47 N/N-CoO.…”

An inclusive perspective on the recent development of tungsten‐based catalysts for overall water‐splitting : A review

“…These materials have been reported to have large electrical conductivity, high catalytic activity, and improved poisoning resistance for several electrochemical reactions 18‐20 . It has been shown in several recent experimental studies that the presence of transition metals such as tungsten, iron, nickel, and cobalt increases the electron density across the metal centers, whereas anions such as boron, nitrogen, and phosphorus highly improve chemical bonding to promote mechanical and thermal stability and catalytic resilience, as well as to activate the basal planes and increase of interlayer spacing 20‐23 . The bonding of transition metals with phosphorous, carbon, nitrogen, and Sulphur not just induces a weak “ligand effect” which allows for an excellent activity for the dissociation of H 2 , then also provides reasonable bonds to trap catalytic intermediates and avoid the inactivation of catalysts 24 .…”