Lithium–carbon dioxide (Li–CO₂) batteries have attracted considerable attention due to their high theoretical energy densities and potential for capturing and converting CO₂ toward net-zero carbon dioxide emissions. However, the reversible cycling capability of Li–CO₂ batteries is greatly limited by the sluggish kinetics of the CO₂ evolution reaction (CO₂ER), which leads to excessive charge voltages exceeding 4.0 V, thus significantly hindering the practical advancement of the battery technology. Herein, we report dual-active-site AuRu catalysts supported on TiO₂ nanorod arrays, grown on carbon nanofiber, where TiO₂ layers effectively prevent carbon corrosion and the electronic synergy of the dual active site design comprising Au and Ru can lower the reaction energy barriers of the CO₂ reduction reaction (CO₂RR) and CO₂ER. Calculation results reveal that this synergy gives rise to complementary catalytic roles: Au facilitates CO₂ activation, whereas Ru promotes Li₂CO₃ breakdown, collectively enhancing the overall reaction kinetics. Consequently, Li–CO₂ batteries employing AuRu/TiO₂ cathode deliver an ultralong cycle life exceeding 1100 cycles (~ 2200 h), low charge voltages (2.9–3.1 V), high energy efficiency (~ 77.9%), and excellent stability at elevated temperatures. This work establishes a generalizable catalyst-support strategy for long lifespan metal–CO₂ batteries, offering a promising route toward high-performance carbon neutral energy storage devices.

Methods of seawater desalination and carbon dioxide (CO₂) reduction using clean and renewable energy have attracted much attention withing the reducing fresh water and growing CO₂ concentration. Here, we propose a synergistic method for solar-driven desalination and CO₂ reduction at the surface of sea using a three-dimensional titanium oxide-gold semiconductor/metal (TiO₂-Au NW/NPs (NW: nanowire, NP: nanoparticle)) photothermal conversion membrane that can efficiently harvest a broad solar spectrum (200 to 2500 nm, 94%) to undertake the conversion of light-to-heat and light-to-electricity. The TiO₂-Au NW/NPs membrane demonstrated a high solar vapor conversion efficiency of ~ 90%, CO₂ reduction yields of 0.066 μmol·cm⁻² CH₄ and 0.015 μmol·cm⁻² CO within 5 h. In addition, the membrane efficiently evaporated seawater with different salt concentrations to produce drinking water which meet World Health Organization (WHO) and US Environmental Protection Agency (EPA) standards. This work provides an integrated solution for solar desalination and CO₂ reduction at the surface of sea to reduce the harm to marine life caused by ocean acidification while producing pure water.