High-entropy oxides receive significant attention owing to their “four effects”. However, they still suffer from harsh construction conditions such as high temperature and high pressure and present a block-like structure. Herein, in this work, Ni-Mn-Cu-Co-Fe-Al high-entropy layered oxides (HELOs) with a layered nanosheet structure were constructed by a simple pathway of topological transformation under relatively low temperature (300 °C) with six-membered Ni-Mn-Cu-Co-Fe-Al layered double hydroxides (LDHs) precursors, which exhibited an outstanding activity and excellent selectivity for CO₂ photoelectroreduction (obtaining the highest carbon monoxide yield of 909.55 μmol·g⁻¹·h⁻¹ under −0.8 V vs. reversible hydrogen electrode (RHE), which is almost twice that of pure electrocatalysis). In addition, the charging voltage of a photo-assisted Zn-CO₂ battery with HELOs as electrode was reduced from 2.62 to 2.40 V; the discharging voltage of the battery was increased from 0.51 to 0.59 V with the assistance of illumination. The improvement of round-trip efficiency of the battery indicates that light played a positive role in both the charging and discharging processes. This study not only lays an important foundation for the development of high-entropy oxides but also expands their application in the field of photoelectrochemistry.

Oxygen reduction reaction (ORR) plays a pivotal role in advanced electrochemical energy conversion devices. However, the ORR conversion efficiency is extremely limited. The major obstacles originate from the adsorption and activation of O₂ on the electrode surface. A novel nanocomposite catalyst, photosensitizers (PS) meso-tetraphenylporphyrin iron(III) chloride (FePcCl)/NiCoFe-layered double hydroxides (NiCoFe-LDHs) is designed in this study. Herein, owing to excellent oxygen molecules activation ability and remarkable illumination absorption feature, FePcCl/NiCoFe-LDHs is employed to uncover the relationship between the intrinsic ORR activity and PS behaviour. Interestingly, the reaction mechanism of singlet ¹O₂ is proposed owing to the combination of electrochemical ORR catalysed via LDHs and PS. The boosted cathodic ORR properties exhibit singlet ¹O₂ dependent response arising from the synergistic effect to selectively produce active intermediates in alkaline medium. This work imparts the promising new mechanism about the high 4-electron ORR selectivity via material design, which will guide the development of photo-assisted energy conversion devices.

In contrast to reactive oxygen species (ROS), the generation of oxygen-irrelevant free radicals is oxygen- and H₂O₂-independent in cell, which can offer novel opportunities to maximum the chemodynamic therapy (CDT) efficacy. Herein, an H₂O₂-independent “functional reversion” strategy based on tumor microenvironment (TME)-toggled C-free radical generation for CDT is developed by confining astaxanthin (ATX) on the NiFe-layered double hydroxide (LDH) nanosheets (denoted as ATX/LDH). The unique ATX/LDH can demonstrate outstanding TME-responsive C-free radical generation performance by proton coupled electron transfer (PCET), owing to the specific ATX activation by unsaturated Fe sites on the LDH nanosheets formed under TME. Significantly, the Brönsted base sites of LDH hydroxide layers can promote the generation of neutral ATX C-free radicals by capturing the protons generated in the ATX activation process. Conversely, ATX/LDH maintain antioxidant performance to prevent normal tissue cancerization due to the synergy of LDH nanosheets and antioxidative ATX. In addition, C-free radical can compromise the antioxidant defense in cells to the maximum extent, compared with ROS. The free radicals burst under TME can significantly elevate free radical stress and induce cancer cell apoptosis. This strategy can realize TME-toggled C free radical generation and perform free radical stress enhanced CDT.

Ammonia is important for industrial development and human life. The traditional Haber Bosch method converts nitrogen into ammonia gas at high temperatures and pressures, causing serious pollution and greenhouse gas emissions. These problems prompt the nitrogen fixation method to proceed in a sustainable way. Ultrathin Ni/V-layered double hydroxides (Ni/V-LDHs) nanosheets with different proportions were prepared successfully for photocatalystic reduction of nitrogen to ammonia, through aqueous miscible organic solvent method (AMO) to achieve the higher surface area and rich oxygen vacancies, containing more carriers and active sites to enhance nitrogen reduction. And the optimal catalyst of Ni/V-LDHs 11 AMO possesses the highest photocatalytic efficiency (176 µmol·g⁻¹·h⁻¹), indicating its potential application prospects in catalyst fields. Consequently, this work achieves an environmentally friendly, low-cost and efficient conversion method for nitrogen reduction to ammonia through solar energy.

Lithium-sulfur batteries are promising electrochemical energy storage devices because of their high theoretical specific capacity and energy density. An ideal sulfur host should possess high conductivity and embrace the physical confinement or strong chemisorption to dramatically suppress the polysulfide dissolution. Herein, uniform TiN hollow nanospheres with an average diameter of ~160 nm have been reported as highly efficient lithium polysulfide reservoirs for high-performance lithium-sulfur batteries. Combining the high conductivity and chemical trapping of lithium polysulfides, the obtained S/TiN cathode of 70 wt.% sulfur content in the composite delivered an excellent long-life cycling performance at 0.5C and 1.0C over 300 cycles. More importantly, a stable capacity of 710.4 mAh·g?1 could be maintained even after 100 cycles at 0.2C with a high sulfur loading of 3.6 mg·cm?1. The nature of the interactions between TiN and lithium polysulfide species was investigated by X-ray photoelectron spectroscopy studies. Theoretical calculations were also carried out and the results revealed a strong binding between TiN and the lithium polysulfide species. It is expected that this class of conductive and polar materials would pave a new way for the high-energy lithium-sulfur batteries in the future.