Copper-based materials are promising electrocatalysts for CO₂ reduction. Prior studies show that the mixture of copper (I) and copper (0) at the catalyst surface enhances multi-carbon products from CO₂ reduction; however, the stable presence of copper (I) remains the subject of debate. Here we report a copper on copper (I) composite that stabilizes copper (I) during CO₂ reduction through the use of copper nitride as an underlying copper (I) species. We synthesize a copper-on-nitride catalyst that exhibits a Faradaic efficiency of 64 ± 2% for C₂₊ products. We achieve a 40-fold enhancement in the ratio of C₂₊ to the competing CH₄ compared to the case of pure copper. We further show that the copper-on-nitride catalyst performs stable CO₂ reduction over 30 h. Mechanistic studies suggest that the use of copper nitride contributes to reducing the CO dimerization energy barrier—a rate-limiting step in CO₂ reduction to multi-carbon products.

Endowing three-dimensional (3D) displays with flexibility drives innovation in the next-generation wearable and smart electronic technology. Printing circularly polarized luminescence (CPL) materials on stretchable panels gives the chance to build desired flexible stereoscopic displays: CPL provides unusual optical rotation characteristics to achieve the considerable contrast ratio and wide viewing angle. However, the lack of printable, intense circularly polarized optical materials suitable for flexible processing hinders the implementation of flexible 3D devices. Here, we report a controllable and macroscopic production of printable CPL-active photonic paints using a designed confining helical co-assembly strategy, achieving a maximum luminescence dissymmetry factor ( g _lum ) value of 1.6. We print customized graphics and meter-long luminous coatings with these paints on a range of substates such as polypropylene, cotton fabric, and polyester fabric. We then demonstrate a flexible textile 3D display panel with two printed sets of pixel arrays based on the orthogonal CPL emission, which lays an efficient framework for future intelligent displays and clothing.