Fabrication of Cerium-Doped CoMoP/MoP@C Heterogeneous Nanorods with High Performance for Overall Water Splitting

Abstract

Doping rare-earth metals or introducing carbon into transition metal phosphides (TMPs) can promote the property and stability of water electrolysis. An original composite nanostructure, cerium-doped and carbon-coated CoMoO4 (Ce-doped CoMoO4@C), was obtained by a simple hydrothermal and annealing process successively. Subsequently, chemical vapor deposition (CVD) was adopted to synthesize carbon-coated and cerium-doped CoMoP/MoP (Ce-doped CoMoP/MoP@C) with diammonium hydrogen phosphate as the phosphorus source. Ce-doped CoMoP/MoP@C displayed superb bifunctional HER and OER catalytic performance under alkaline conditions. The overpotential η10, Tafel slope, and double-layer capacitance (C dl) for the OER were 287.0 mV, 74.4 mV dec–1, and 10.44 mF cm–2, while for the HER, these values were 188.0 mV, 72.2 mV dec–1, and 33.00 mF cm–2, respectively. Meanwhile, only 1.59 V (@10 mA cm–2) was needed to drive the entire water splitting. In addition, there was no apparent attenuation after electrolytic catalysis for 12 h continuously. The superb performance and endurance gave credit to the cooperative effect between carbon materials and metal phosphides and the optimized electronic structure by the incorporation of the Ce element.

Synergistically Coupled CoMo/CoMoP Electrocatalyst for Highly Efficient and Stable Overall Water Splitting

“…The P 2p spectrum shows the disappearance of the metal phosphide peak and the retention of the PO x peak (133.5 eV). These experimental phenomena are consistent with the established OER mechanism, whereby transition metals and their phosphides form oxyhydroxides in alkaline media. , Under alkaline conditions (1 M KOH), the mechanism of metal oxyhydroxide (MOOH) formation in OER studies is shown in equations as follows …”

“…As shown in the further magnified HRTEM images, the distinct lattice fringes with a spacing of 2.13 Å correspond to interplanar distances of the CoMo (111) plane (Figure f1, f2) . Moreover, the lattice spacings of 2.31 and 2.84 Å can be assigned to the (112) and (111) planes of CoMoP (Figure f3,f4), respectively. , The EDS results show the presence of Co, Mo, and P elements (Figure S4), and the proportion of elements is in general agreement with the ICP test results (Table S1). The scanning transmission electron microscopy-high-angle annular dark-field (STEM-HAADF) and the elemental mappings of CoMo/CoMoP/NF show an overall homogeneous distribution of Co, Mo, and P elements across the nanosheet as well as a concentration of Co and Mo elements in the region of the alloy particles (Figure g).…”

“…Figure b clearly compares the overpotentials at both 10 and 50 mA cm –2 current densities and clearly shows that a lower overpotential is required for CoMo/CoMoP/NF. The current OER electrocatalytic activity of CoMo/CoMoP/NF is superior to many recently reported novelty OER catalysts (Figure h), such as Ce-doped CoMoP/MoP@C (287 mV), Ni-Cu-P@Ni-Cu (270 mV), and Co-Mo 2 C@NC (338 mV), and so on. ,,,,,− In addition, we further compared the properties of CoMo/CoMoP/NF with monometallic phosphide/alloy as well as investigated the effect of different alloy ratios (different electrodeposition times) on the performance of the samples. As shown in Figure S9, the CoMo/CoMoP/NF electrocatalyst still shows absolute advantages in terms of both HER and OER, indicating the superiority of the bimetallic phosphides and the importance of a suitable interface for the catalytic activity.…”

Sandwich-like CoMoP2/MoP heterostructures coupling N, P co-doped carbon nanosheets as advanced anodes for high-performance lithium-ion batteries

“…3g, two peaks seated at 229.2 and 231.5 eV indicate the Mo-P bond, turning out the intense incorporative interaction between Mo and P atoms. Moreover,peaks at 228.3, 232.6, 232.9, and 236 eV are indexed to Mo 4+ and Mo 6+ signals, mainly because of the surface oxidation of MoP originated from high surface energy [40][41][42]. As presented in P 2p region in Fig.…”

Manganese Molybdenum Oxide Micro Rods Adorned Porous Carbon Hybrid Electrocatalyst for Electrochemical Determination of Furazolidone in Environmental Fluids

“…Metal molybdates are a family of inorganic materials that have gotten a lot of interest recently because of their widespread use in fields like lithium storage [28], HER [29], hybrid devices [30], luminescence property [31], and heavy metal detection sensors [32]. In particular, MnMoO 4 has received special attention due to its inexpensive cost, exceptional stability, outstanding chemical properties, low toxicity, and abundant oxidation, as well as the original price state of Mo and Mn compared to that of binary transition metal oxides such as FeMoO 4 [33], CuMoO 4 [34], NiMoO 4 [35], CoMoO 4 [36], and others.…”