Bimetallic Atom Dual-Doped MoS₂-Based Heterostructures as a High-Efficiency Catalyst To Boost Solar-Assisted Alkaline Seawater Electrolysis

Abstract

For a large-scale production of green hydrogen via water splitting, seawater, because of its low-cost and abundant nature, is an attractive alternative to freshwater. An effective coordination purposely modulated electrocatalyst with high catalytic activity and selectivity is required to overcome the undesirable chlorine ion oxidation reaction that critically hampers electrolysis performance at the anode side. Herein, we reveal that dual-atomically dispersed palladium (Pd) and ruthenium (Ru) over two-dimensional MoS 2 shelled CoNi alloy nanowires can obtain tailored properties to impressively improve hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities. The catalyst exhibits overpotentials for the HER and OER as low as 89 and 230 mV at 10 mA•cm −2 in alkaline freshwater, respectively, along with favorable stability. Theoretical studies indicate that dual-atomically dispersed Pd and Ru in MoS 2 modifies S sites to be advantageous centers for optimum hydrogen adsorption, thus improving the catalytic activities. The electrolyzer of CoNi@MoS 2 − Pd SA Ru SA(+,−) delivers a current response of 10 mA•cm −2 at small cell voltages of 1.45, 1.54, and 1.54 V along with high solar-tohydrogen conversion efficiencies of 17.66, 17.71, and 18.14% in alkaline freshwater, simulated seawater, and natural seawater, respectively, beyond Pt/C (−) //RuO 2(+) behaviors as well as previous reports.

Recent Advances in Doping Strategies to Improve Electrocatalytic Hydrogen Evolution Performance of Molybdenum Disulfide

“…According to recent research by Saikat Bolar et al., two-dimensional MoS 2 -coated CoNi alloy nanowires with dual-atomically distributed Pd and Ru can acquire customized characteristics that greatly enhance HER performance (Figure a) . In alkaline freshwater, the catalyst exhibits overpotentials for the HER as low as 89 at 10 mA cm –2 , showing good stability as shown in Figure b and c. According to theoretical research, MoS 2 ’s dual-atomically scattered Pd and Ru change S sites into ideal foci for hydrogen adsorption, boosting the catalytic activities (Figure d).…”

“…(d) Δ G H* value of the different material models. Reproduced with permission from ref . Copyright 2023 American Chemical Society.…”

2D layered double hydroxides and transition metal dichalcogenides for applications in the electrochemical production of renewable hydrogen

“…Again, the main metal-based doping or elements involve Ni, Co and Fe. 151,152 For example, highconducting CoNi nanowires were covered with MoS 2 , and then atomically dispersed Pd and Ru were decorated over the MoS 2 to give a bifunctional electrocatalyst for both the HER and OER. 151 A cell potential of 1.54 V (at 10 mA cm À2 ) in alkaline seawater was obtained with a 92% retention of the current over a 40 h period.…”

Highly efficient and durable P, Ru–CeO2 self-supporting electrodes toward industrial-level hydrogen production

“…To date, there have been significant advances in developing efficient electrolytic saline-alkali water catalysts, including metal nitrides, 25,26 phosphides, 27,28 sulfides, 29,30 and so on. To reach the level of industrial water splitting, the electrode material must meet the following requirements: (1) low cost; (2) exceptional catalytic activity (>1000 mA cm −2 ); (3) excellent long-term stability (>100 h and >300 mA cm −2 ) and corrosion resistance to Cl − (>3.5%).…”