Panpan Zhang

Currently, conventional dimethoxymethane synthesis methods are environmentally unfriendly. Here, we report a photo-redox catalysis system to generate dimethoxymethane using a silver and tungsten co-modified blue titanium dioxide catalyst (Ag.W-BTO) by coupling CO₂ reduction and CH₃OH oxidation under mild conditions. The Ag.W-BTO structure and its electron and hole transfer are comprehensively investigated by combining advanced characterizations and theoretical studies. Strikingly, Ag.W-BTO achieve a record photocatalytic activity of 5702.49 µmol g⁻¹ with 92.08% dimethoxymethane selectivity in 9 h of ultraviolet-visible irradiation without sacrificial agents. Systematic isotope labeling experiments, in-situ diffuse reflectance infrared Fourier-transform analysis, and theoretical calculations reveal that the Ag and W species respectively catalyze CO₂ conversion to *CH₂O and CH₃OH oxidation to *CH₃O. Subsequently, an asymmetric carbon-oxygen coupling process between these two crucial intermediates produces dimethoxymethane. This work presents a CO₂ photocatalytic reduction system for multi-carbon production to meet the objectives of sustainable economic development and carbon neutrality.

The key to hindering the commercial application of Ni-rich layered cathode is its severe structural and interface degradation during the undesired phase transition (hexagonal to hexagonal (H2 → H3)), degenerating from the build-up of mechanical strain and undesired parasitic reactions. Herein, a perovskite Li_0.35La_0.55TiO₃ (LLTO) layer is built onto Ni-rich cathodes crystal to induce layered@spinel@perovskite heterostructure to solve the root cause of capacity fade. Intensive exploration based on structure characterizations, in situ X-ray diffraction techniques, and first-principles calculations demonstrate that such a unique heterostructure not only can improve the ability of the host structure to withstand the mechanical strain but also provides fast diffusion channels for lithium ions as well as provides a protective barrier against electrolyte corrosion. Impressively, the LLTO modified LiNi_0.9Co_0.05Mn_0.05O₂ cathode manifests an unexpected cyclability with an extremely high-capacity retention of ≈ 94.6% after 100 cycles, which is superior to the pristine LiNi_0.9Co_0.05Mn_0.05O₂ (79.8%). Furthermore, this modified electrode also shows significantly enhanced cycling stability even withstanding a high cut-off voltage of 4.6 V. This surface self-reconstruction strategy provides deep insight into the structure/interface engineering to synergistically stabilize structure stability and regulate the physicochemical properties of Ni-rich cathodes, which will also unlock a new perspective of surface interface engineering for layered cathode materials.