ZnO, aside from TiO₂, has been considered as a promising material for purification and disinfection of water and air and remediation of hazardous waste, owing to its high activity, environment-friendly feature and lower cost. However, their poor visible light utilization greatly limited their practical applications. Herein, we demonstrate the fabrication of different aspect ratios of the ZnO nanorods with surface defects by mechanical-assisted thermal decomposition method. The experiments revealed that ZnO nanorods with higher aspect ratio and surface defects show significantly higher photocatalytic performances.

High-safety and low-cost aqueous zinc-ion batteries (ZIBs) are an exceptionally compelling technology for grid-scale energy storage, whereas the corrosion, hydrogen evolution reaction and dendrite growth of Zn anodes hamper their further development, which are derived from the decomposition of active water molecules belonging to Zn²⁺ solvation structures in electrolytes. In recent years, strategies of regulating Zn²⁺ solvation shells in electrolytes have been demonstrated to effectively suppress the above-mentioned issues, and fruitful achievements have been made. However, there is a lack of systematic summary on the functional mechanisms and solvation structure evolution of electrolytes or electrolyte additives. Herein, this review gives a comprehensive introduction of the solvation structure regulation strategies based on electrolyte engineering for dendrite-free and side reaction-suppressed ZIBs, including high-concentration electrolytes, deep eutectic solvents, ionic liquids, functional additives, solid-state electrolytes and super-saturated electrolyte layers, particularly an in-depth and fundamental understanding of the effects and mechanisms of electrolyte modification on Zn²⁺ solvation shells. Furthermore, the general performance metrics of the above-mentioned strategies, potential directions and perspectives for further research are proposed.

To solve the poor cycling stability of zinc ion batteries (ZIBs) caused by the growth of zinc (Zn) dendrites, a novel method of separator modification is proposed. Herein, graphene oxide (GO), which has many outstanding properties, is applied as a modified material to a glass fiber (GF) separator using a simple vacuum filtration method. A stable and dendrite-free Zn anode can be obtained after 500 cycles in a Zn//Zn symmetrical battery when using a modified separator (GF/GO1), which is mainly owing to the preferential growth of the non-protruding crystal planes of the zinc metal and the uniform nucleation of zinc ions under the action of GO. As proof of concept, full Zn//MnO₂ batteries with a GF/GO1 separator exhibited a high specific capacity of 126 mA h g⁻¹ at 0.1 A g⁻¹, a high energy density of 327.5 W h kg⁻¹ (power density of 0.517 W kg⁻¹), and a high power density of 20.8 kW kg⁻¹ (energy density of 253.8 W h kg⁻¹), demonstrating significant improvements compared with the unmodified GF separator. Meanwhile, ZIBs with a GF/GO1 separator exhibited excellent long-term stability with less than 25% capacity fade over 500 cycles at a current density of 0.5 A g⁻¹. ZIBs with a GF separator retain only 37% of their initial capacity after 100 cycles. Furthermore, the GF/GO1 separator can also help to improve the cycle performance and rate performance of lithium metal batteries and to achieve a dendrite-free lithium anode. Full batteries of Li//GF/GO1//LiCoO₂ show improved rate and cycling capabilities. A higher energy density of 537.1 W h kg⁻¹ at 0.04 kW kg⁻¹ and higher power density of 1.4 kW kg⁻¹ at 264.6 W h kg⁻¹ can be achieved with a GF/GO1 separator, which is better than many Li metal batteries. This modification of the separator provides an effective approach to designing next-generation batteries exhibiting excellent rate and cycling capabilities, and high energy and power densities.

The uncontrolled dendrite growth and detrimental parasitic reactions of Zn anodes currently impede the large-scale implementation of aqueous zinc ion batteries. Here, we design a versatile quasi-solid-state polymer electrolyte with highly selective ion transport channels via molecular crosslinking of sodium polyacrylate, lithium magnesium silicate and cellulose nanofiber. The abundant negatively charged ionic channels modulate Zn²⁺ desolvation process and facilitate ion transport. Moreover, an in-situ formed Zn-Mg-Si medium-entropy alloy on Zn anode allows for an improved Zn nucleation kinetics and homogeneous Zn deposition. These combined advantages of the polymer electrolyte enable Zn anodes to achieve an average Coulombic efficiency of 99.7 % over 2400 cycles and highly reversible cycling up to 600 h with large depth of discharge of 85.6%. The resultant Zn | |V₂O₅ offers a stable long-term cycling performance and its pouch cell achieves a cycling capacity of 1.13 Ah at industrial-level loading mass of 31.3 mg.