Sodium metal batteries are attracting increasing attention on account of their high energy densities as well as the abundance of sodium-based resources. However, the uneven metallic deposition and dendrite formation during cycling hinder the application of sodium metal anodes. Carbon skeletons have been reported in the literature to mitigate the dendrite formation during the plating and stripping of metallic sodium. Still, the role played by different carbon structural features (i.e., pores vs. defects) and relative mechanisms are not well understood, preventing the controllable interface engineering at the anode side. Here, we have rationally designed the structural features of sustainable carbon skeletons from a renewable precursor to unveil the roles of defects and pores for metallic deposition. The obtained carbon skeleton with rich defects and negligible pores exhibits the best performance when applied to protect metal anodes. After long cycling (>1200 hours), the retained high Coulombic efficiency (∼99.9%) of the plating and stripping processes indicates the importance of defects for inducing uniform metallic deposition. Combined with different types of cathodes (e.g., Prussian blue and sulfur), “anode-less” sodium metal batteries with enhanced electrochemical performance are also demonstrated in terms of sustainability.

A one-pot synthesis method for the fabrication of biomass-derived activated carbon–zinc oxide (ZAC) nanocomposites using sugarcane bagasse as a carbon precursor and ZnCl₂ as an activating agent is reported. For the first time, we used ZnCl₂ as not only an activating agent and also for the synthesis of ZnO nanoparticles on the AC surface. ZAC materials with varying ZnO loading were prepared and characterized by a variety of analytical and spectroscopic techniques such as FE-SEM, FE-TEM, XRD, EA, XPS, and Raman spectroscopy. ZAC-modified glassy carbon electrodes (GCEs) were found to exhibit remarkable electrochemical properties for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) as well as hazardous pollutants such as hydrogen peroxide (H₂O₂) and hydrazine (N₂H₄) with desirable sensitivity, selectivity, and detection limits. Moreover, ZAC-modified stainless steel electrodes also showed superior performances for supercapacitor applications. The ZAC nanocomposites, which may be mass produced by the reported facile direct route from sugarcane bagasse, are not only eco-friendly but also cost-effective, and thus, are suitable as a practical platform for bio-sensing and energy storage applications.

Palladium nanoparticles (Pd NPs) have attracted considerable attention recently for their excellent catalytic properties in various catalysis reactions. However, Pd NPs have some drawbacks, including their high cost, susceptibility to deactivation, and the possibility of poisoning by intermediate products. Herein, Pd nanoparticles with an average diameter of 6.5 nm were successfully incorporated on electronically transparent 2D MXene (Ti₃C₂Ti_x) nanosheets (Pd-MXene) by microwave irradiation. Considering the synergetic effects of ultra-fine Pd NPs, together with the intrinsic properties of 2D MXene, the obtained Pd-MXene showed a specific surface area of 97.5 m²g⁻¹ and multiple pore channels that enabled excellent electrocatalytic activity for the reduction of CO₂. Further, the 2D Pd-MXene hybrid nanocatalyst enables selective electroreduction of CO₂ into selective production of CH₃OH in ambient conditions by multiple electron transfer. A detailed explanation of the CO₂RR mechanism is presented, and the faradic efficiency (FE) of CH₃OH is tuned by varying the cell potential. Recyclability studies were conducted to demonstrate the practical application of CO₂ reduction into selective production of CH₃OH. In this study, metal and MXene interfaces were created to achieve a highly selective electroreduction of CO₂ into fuels and other value-added chemical products.