Laser-sculptured ultrathin transition metal carbide layers for energy storage and energy harvesting applications.

Zang, Xining; Jian, Cuiying; Zhu, Taishan; Fan, Zheng; Wang, Wanlin; Wei, Minsong; Li, Buxuan; Follmar Diaz, Mateo et al. · Nat Commun · 2019

basic_science · Level V

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Abstract

Ultrathin transition metal carbides with high capacity, high surface area, and high conductivity are a promising family of materials for applications from energy storage to catalysis. However, large-scale, cost-effective, and precursor-free methods to prepare ultrathin carbides are lacking. Here, we demonstrate a direct pattern method to manufacture ultrathin carbides (MoC<sub>x</sub>, WC<sub>x</sub>, and CoC<sub>x</sub>) on versatile substrates using a CO<sub>2</sub> laser. The laser-sculptured polycrystalline carbides (macroporous, ~10-20 nm wall thickness, ~10 nm crystallinity) show high energy storage capability, hierarchical porous structure, and higher thermal resilience than MXenes and other laser-ablated carbon materials. A flexible supercapacitor made of MoC<sub>x</sub> demonstrates a wide temperature range (-50 to 300 °C). Furthermore, the sculptured microstructures endow the carbide network with enhanced visible light absorption, providing high solar energy harvesting efficiency (~72 %) for steam generation. The laser-based, scalable, resilient, and low-cost manufacturing process presents an approach for construction of carbides and their subsequent applications.