Tailoring durable MnOx-based electrodes for high-performance electrocatalytic function for next-generation electrocatalysis applications

Materials for Renewable and Sustainable Energy https://doi.org/10.1007/s40243-024-00290-7 (2025) 14:12 ORIGINAL PAPER Tailoring durable MnOx‑based electrodes for high‑performance electrocatalytic function for next‑generation electrocatalysis applications Hashem Tayeba1 · Roya Kiani‑Anbouhi1 · Neda Royaei2 Received: 16 August 2024 / Accepted: 18 December 2024 © The Author(s) 2025 Abstract This study introduces a high-performance electrode coated with M nOx compounds to enhance the HER reaction. The active and precipitated M nOx species facilitate interconnected electron transport throughout the Ti electrodes. The tailored M nOx electrodes exhibited a significant reduction in Rct (69.7%), superior Cdl (31.6%), and a notably lower Nyquist ring compared to traditional Ti electrodes, confirming their excellent electrocatalytic performance in C l− and NaCl production. Additionally, LSV and PDP analysis demonstrated that the M nOx electrodes achieved a 53.9% decrease in Tafel slopes (from 139 mV/ decade to 64 mV/decade), lower activity potentials, and robust corrosion resistance (99.4%), indicating faster kinetics and higher efficiency. High-resolution FESEM and contact angle images revealed that the MnOx electrodes possess uniform porous networks and semi-super hydrophilic function, optimizing H2 release and expanding the interfacial area for electron transfer. Finally, the Ti electrodes with advanced M nOx coatings can serve as reliable, cost-effective, and efficient candidates for use as regenerating electrodes in electrocatalytic industries. Moreover, the novel MnOx/rGO composites are versatile materials used as catalysts in chemical reactions, effective electrodes in energy storage devices, sensitive gas sensors, and for water treatment to remove contaminants. Keywords MnOx electrode · Electrocatalytic activity · HER reaction Introduction In the current landscape, a multitude of composite materials, including metal alloys and hybrid oxide coatings, are employed in electrocatalytic dimensionally stable anodes (DSAs). These DSAs are pivotal in state-of-the-art electrical applications such as batteries, supercapacitors, and fuel cells, primarily for hydrogen gas generation. They also serve a vital role in the Chlor-Alkali sector, aiding in the synthesis of chlorine gas, sodium hydroxide, and chlorate compounds * Roya Kiani‑Anbouhi * Neda Royaei 1 Department of Chemistry, Faculty of Science, Imam Khomeini International University, P.O. Box 34148‑96818, Qazvin, Iran 2 Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute (NSTRI), P.O. Box 14155‑1339, Tehran, Iran [1–3]. Technological advancements have intensified efforts to curtail energy use, especially in sectors with high demand such as Chlor-Alkali manufacturing. Given that chlorine and related chemicals rank among the most utilized globally, optimizing production techniques is crucial [4]. Titaniumbased electrodes are preferred in various industries due to their superior conductivity, stability, affordability, and electrocatalytic efficiency [5, 6]. Electrodes coated with rare-earth oxides, such as RuO2 and IrO2, particularly when applied to Ti anodes, significantly improve electrochemical efficacy [7, 8]. The realm of electrochemistry has witnessed a growing acknowledgment of manganese oxides ( MnOx) for their superior electrochemical attributes, environmental sustainability, and cost-efficiency. M nOx, an abundant and versatile transition metal oxide, has been extensively researched and acclaimed for its catalytic prowess and electrochemical potential. The derivatives of MnOx, distinguished by their expansive specific surface area, exceptional conductivity, and formidable stability, are deemed highly compatible for use in electrocatalytic processes. The electrochemical versatility of MnOx, attributed to its capacity for multiple valence Vol.:(0123456789) 12 Page 2 of 14 states and catalytic flexibility, renders it an optimal material for electrodes used in energy storage and conversion systems. The strategic application of M nOx coatings onto conductive substrates has been empirically validated to enhance electrocatalytic activity and extend operational longevity. In practical applications, electrodes enhanced with M nOx coatings have been observed to significantly elevate the efficiency of batteries, supercapacitors, and hydrogen fuel cells, as documented in recent studies [9–11]. Furthermore, the specific variant MnO2 has recently garnered significant interest due to its unique properties, which have been leveraged in a variety of industrial applications, most notably within the Chlor-Alkali sector [12]. These coatings are celebrated for their contribution to the advancement of electrochemical technologies, offering promising avenues for industrial innovation and sustainability. The fabrication of electrodes composed of M nOx is typically executed through sol–gel methodologies, providing a meticulous and regulated technique for the application of MnOx films onto Ti substrates. The employment of the spin-coating method, a widely adopted technique within this field, guarantees the attainment of homogenous M nOx layers, which is pivotal for the maintenance of uniform electrocatalytic activities. Previous studies have corroborated that the integration of multi-walled carbon nanotubes (MWCNTs) within MnOx/Ti electrodes substantially augments the efficiency of electrocatalytic oxidation processes. In addition, the infusion of rare earth metals, such as cerium, into the MnOx sol–gel coatings that are deposited onto porous Ti membrane electrodes has been evidenced to enhance their electrocatalytic capabilities. The performance of MnOx-based electrodes in electrocatalytic applications is deemed a crucial aspect, with corrosion resistance being of utmost importance, particularly within the stringent conditions of the chlor-alkali industry. Many research has revealed that MnOx-based electrodes demonstrate exceptional corrosion resistance, which can be ascribed to the formation of a stable oxide layer on the electrode’s surface. Moreover, the nOx-based kinetics of the H 2 evolution reaction (HER) on M electrodes has been extensively investigated. The development of advanced HER electrocatalysts is tailored to align with the chlor-alkali reaction, with the objective of achieving H2 production that is not only cost-effective but also environmentally benign. Recent studies have concentrated on enhancing MnOx-based electrodes for their electrocatalytic efficiency. Notably, Hayfield et al. investigated noble metal/ oxide coatings on Ti electrodes, essential for chloride-rich environments, with ruthenium dioxide coatings showing potential in various chlor-alkali cells [13]. Cui et al. highlighted the need for corrosion-resistant materials in seawater electrolysis due to chloride-induced corrosion, with mixed metal oxides and MnOx-coated structures improving selectivity for o (...truncated)