Ru-Doped CuO/MoS₂ Nanostructures as Bifunctional Water-Splitting Electrocatalysts in Alkaline Media

Abstract

Molybdenum-based materials have attracted considerable attention for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) as potential alternatives to noble materials. In view of this, the present work is focused on the synthesis of mixed-phase (2H/1T) molybdenum sulfide (MoS2) using a simple facile hydrothermal method followed by its impregnation with CuO and doping with ruthenium. The nanostructured Ru-doped CuO/MoS2 (MSCR) prepared in this manner has been characterized and studied for HER and OER in an alkaline medium. The MSCR catalyst showed overpotentials of ∼198 mV, 201 mV, and 1.68 V to achieve 10 mA/cm2 current density in HER, OER, and overall water splitting. respectively. Tafel slopes of MSCR in HER (113 mV dec–1) and OER (229 mV dec–1) were found to be comparable enough to those of Pt/C and Ir/C, respectively. Such lower overpotentials and Tafel slopes arise as a consequence of proliferated electrochemical active surface area; different electronic couplings of molybdenum, copper, and ruthenium; abundant vacancies and defects; homogeneous distribution of copper oxide; higher conductivity of the structure; and unique ultrathin 3d flowerlike morphology.

Synthesis of CuMoS micro‐rods material as efficient bifunctional electrocatalyst for overall water splitting

“…Likewise, the S 2p deconvolution spectra (Figure 3d) showed peaks at 161.9, 163.2, and 164.7 eV, which were ascribed to S 2p 3/2 , S 2p 1/2 and S 2p 1/2 respectively. Overall XPS spectra representing all existing elements identified as Cu + , Cu 2+ , Mo 4+ , Mo 6+ , and S 2− ions agreed well with those reported, [14e,15–16] proving that CuMoS was present, which could lower the overall potential for OER and HER.…”

SACs on Non‐Carbon Substrates: Can They Outperform for Water Splitting?

“…Metal hydroxides, oxides, sulfides, phosphides and carbides can well work as the host materials to support single metal atoms applied in water splitting cell ( Table 1 ). [ 196–223 ] For instance, the Ru 1 /FeCo LDH as bifunctional HER and OER electrocatalysts delivered an extraordinary performance, including high current densities reaching up to 1200 mA cm −2 and superior stability in the continuous 1000 h test at 1000 mA cm −2 in water splitting cell, [ 204 ] exhibiting the great potential of substitution for commercial precious metal catalysts. Among the most studied bifunctional SACs are those focusing on the construction of precious metal sites towards superior activities aiming for better performance than those of commercial Pt/C and RuO 2 (or IrO 2 ) catalysts, which are applied in alkaline media.…”

Ru Nanoparticle-Anchored MoO2 Nanoflowers as Electrocatalysts for the Hydrogen Evolution Reaction

“…Therefore, exploring highly efficient and low-cost electrocatalysts is still the focus in the investigation field of electrocatalytic hydrogen production. Among noble metals, ruthenium (Ru) and their derivatives are the optimal alternatives to substitute Pt-based catalysts for HER, which benefits from the high catalytic activity and a relatively low price than those of Pt. , To date, C-supported Ru catalysts have been obtained and displayed excellent HER catalytic activities due to abundant activity sites provided by the carbon matrix. , At the same time, semiconductor-supported Ru nanocomposite could further enhance the electrocatalytic activities of Ru by enhancing the interfacial synergistic effect …”