The electrochemical carbon dioxide reduction reaction (CO2RR) provides an attractive approach to convert renewable electricity into fuels and feedstocks in the form of chemical bonds. Among the different CO2RR pathways, the conversion of CO2 into CO is considered one of the most promising candidate reactions because of its high technological and economic feasibility. Integrating catalyst and electrolyte design with an understanding of the catalytic mechanism will yield scientific insights and promote this technology towards industrial implementation. Herein, we give an overview of recent advances and challenges for the selective conversion of CO2 into CO. Multidimensional catalyst and electrolyte engineering for the CO2RR are also summarized. Furthermore, recent studies on the large‐scale production of CO are highlighted to facilitate industrialization of the electrochemical reduction of CO2. To conclude, the remaining technological challenges and future directions for the industrial application of the CO2RR to generate CO are highlighted.

This minireview looks at recent electrodeposition strategies for metal (hydro)oxide design and water oxidation applications, unveiling the unique properties and underlying principles of electrodeposited metal (hydro)oxides in the OER.

On-chip microbatteries have attracted growing attention due to their great feasibility for integration with miniaturized electronic devices. Nevertheless, it is difficult to get both high energy/power densities in microbatteries. An increase in the thickness of microelectrodes may help to boost the areal energy density of device, yet it often leads to terrible sacrifice in its power density due to the longer electron and ion diffusion distances. In this work, a quasi-solid-state on-chip Ni-Zn microbattery is designed based on a hierarchical ordered porous (HOP) Ni@Ni(OH) 2 microelectrode, which is developed by an in situ anodizing strategy. The fabricated microelectrode can optimize ion and electron transport simultaneously due to its interconnected ordered macropore-mesopore network and high electron conductivity. As the thickness of microelectrode increases, the areal energy density of HOP Ni@ Ni(OH) 2 microelectrode shows an ascending trend with negligible sacrifice in power density and rate performance. Impressively, this Ni-Zn microbattery achieves excellent energy/power densities (0.26 mW h cm −2 , 33.8 mW cm −2 ), outperforming most previous reported microenergy storage devices. This study may provide new direction in high-performance and highly safe microenergy storage units for next-generation highly integrated microelectronics.

A novel process to fabricate a carbon-microelectromechanical-system-based alternating stacked MoS @rGO-carbon-nanotube (CNT) micro-supercapacitor (MSC) is reported. The MSC is fabricated by successively repeated spin-coating of MoS @rGO/photoresist and CNT/photoresist composites twice, followed by photoetching, developing, and pyrolysis. MoS @rGO and CNTs are embedded in the carbon microelectrodes, which cooperatively enhance the performance of the MSC. The fabricated MSC exhibits a high areal capacitance of 13.7 mF cm and an energy density of 1.9 µWh cm (5.6 mWh cm ), which exceed many reported carbon- and MoS -based MSCs. The MSC also retains 68% of capacitance at a current density of 2 mA cm (5.9 A cm ) and an outstanding cycling performance (96.6% after 10 000 cycles, at a scan rate of 1 V s ). Compared with other MSCs, the MSC in this study is fabricated by a low-cost and facile process, and it achieves an excellent and stable electrochemical performance. This approach could be highly promising for applications in integration of micro/nanostructures into microdevices/systems.

The electrochemical carbon dioxide reduction reaction (CO2RR) provides an attractive approach to convert renewable electricity into fuels and feedstocks in the form of chemical bonds. Among the different CO2RR pathways, the conversion of CO2 into CO is considered one of the most promising candidate reactions because of its high technological and economic feasibility. Integrating catalyst and electrolyte design with an understanding of the catalytic mechanism will yield scientific insights and promote this technology towards industrial implementation. Herein, we give an overview of recent advances and challenges for the selective conversion of CO2 into CO. Multidimensional catalyst and electrolyte engineering for the CO2RR are also summarized. Furthermore, recent studies on the large‐scale production of CO are highlighted to facilitate industrialization of the electrochemical reduction of CO2. To conclude, the remaining technological challenges and future directions for the industrial application of the CO2RR to generate CO are highlighted.

Bis(trifluoromethanesulfonyl)imide-based ionic liquid (TFSI-IL) electrolyte could endowLi-O 2 batteries with low charging overpotential. However,t heir weak Li + transport ability (LTA)l eads to non-uniform Li deposition. Herein, guided by Sand formula, the LTAo fT FSI-IL electrolyte is greatly enhanced to realizer obust Li deposition through introducing hydrofluoroether (HFE) and optimizing electrolyte component ratios to regulate solvation environment. The solvation environment changes from Li(TFSI) 2À ion pair into ionic aggregate clusters in the optimal electrolyte thanks to the slicing function of HFE towardi onic aggregate network. The transport parameters of Sand formula are synchronously enhanced, resulting in highly robust Li deposition behavior with greatly improved Coulombic efficiency (ca. 97.5 %) and cycling rate (1 mA cm À2 ). Cycling stability of Li-O 2 batteries was greatly improved (a tiny overpotential rise of 64 mV after 75 cycles).

A general graphene quantum dot-tethering design strategy to synthesize single-atom catalysts (SACs) is presented. The strategy is applicable to different metals (Cr, Mn, Fe, Co, Ni, Cu, and Zn) and supports (0D carbon nanosphere, 1D carbon nanotube, 2D graphene nanosheet, and 3D graphite foam) with the metal loading of 3.0-4.5 wt %. The direct transmission electron microscopy imaging and X-ray absorption spectra analyses confirm the atomic dispersed metal in carbon supports. Our study reveals that the abundant oxygenated groups for complexing metal ions and the rich defective sites for incorporating nitrogen are essential to realize the synthesis of SACs. Furthermore, the carbon nanotube supported Ni SACs exhibits high electrocatalytic activity for CO 2 reduction with nearly 100 % CO selectivity. This universal strategy is expected to open up new research avenues to produce SACs for diverse electrocatalytic applications.

The electrochemical performance of layered vanadium oxides is often improved by introducing guest species into their interlayer. Guest species with high stability in the interlayer and weak interaction with Zn2+ during charge/discharge process are desired to promoting reversible Zn2+ transfer. Herein, a universal compensation strategy was developed to introduce various polar organic molecules into the interlayer of AlxV2O5·nH2O by replacing partial crystal water. The high‐polar groups in the organic molecules have a strong electrostatic attraction with pre‐intercalated Al3+, which ensures that organic molecules can be anchored in the interlayer of hydrated vanadates. Simultaneously, the low‐polar groups endow organic molecules with a weak interaction with Zn2+ during cycling, thus liberalizing reversible Zn2+ transfer. As a result, AlxV2O5 with polar organic molecules displays enhanced electrochemical performance. Furthermore, based on above cathode material, a pouch cell was assembled by further integrating a dendrite‐free N‐doped carbon nanofiber@Zn anode, displaying an energy density of 50 Wh kg‐1. This work provides a path for designing stable guest species with a weak interaction with Zn2+ in the interlayer of layered vanadium oxide towards high‐performance cathode materials of aqueous Zn batteries.