Electrocatalytic water splitting to produce hydrogen (H2) is a sustainable way of meeting energy demands at no environmental cost. However, the sluggish anodic reaction imposes a considerable overpotential requirement. By contrast, the electrocatalytic urea oxidation reaction offers the prospect of energy-saving H2 production together with urea-rich wastewater purification. In this work, a 0D/2D Co3O4/Ti3C2 MXene composite was synthesized by a simple solution reaction approach under mild conditions and applied as an efficient and stable electrocatalyst for hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) in basic medium (1 M KOH+0.5 M urea). The Co3O4/Ti3C2 MXene electrodes delivered a current density of 10 mA cm–2 at an overpotential of 124 mV for HER and required 1.40 V to reach 10 mA cm–2 for UOR. The hybrid catalyst could maintain high activity after 40 h continuous catalytic reaction for both UOR and HER. Its catalytic performance was significantly improved compared to that of pure Ti3C2 MXene and Co3O4 solving the problem of insufficient exposure of active sites caused by too large particle size and agglomeration of Co3O4 particles. Notably, Co3O4/Ti3C2 MXene was applied as a bifunctional catalyst for overall urea-containing water splitting, and showed certain energy saving advantages compared with other reported Co-based catalysts. This work provides a strategy for application other than noble metal-based electrode materials for urea-containing wastewater purification coupled with H2 production.
Surface engineering has achieved great success in enhancing the electrochemical activity of Co3O4. However, the previously reported methods always involve high-temperature calcination processes which are prone to induce agglomeration of the nanostructure, leading to the attenuation of performance. In this work, Co3O4 nanowires were successfully modified by a low-temperature NH3/Ar plasma treatment, which simultaneously generated a porous structure and efficient nitrogen doping with no agglomeration. The modified N-CoOx electrode exhibited remarkable performance due to the synergistic effect of the porous structure and nitrogen doping, which provided additional active sites for faradic transitions and improved charge transfer characteristics. The electrode achieved excellent supercapacitive performance with a maximum specific capacitance of 2862 mF/cm2 and superior cycling retention. Furthermore, the assembled asymmetric supercapacitor (N-CoOx//AC) device exhibited an extended potential window of 1.5 V, a maximum specific energy of 80.5 Wh/kg, and a maximum specific power of 25.4 kW/kg with 91% capacity retention after 5000 charge–discharge cycles. Moreover, boosted hydrogen evolution reaction performance was also confirmed by the low overpotential (126 mV) and long-term stability. This work enlightens prospective research on the plasma-enhanced surface engineering strategies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.