The vertically standing, nanoedge-enriched MoOxCy arrays were synthesized through a PECVD process with a salt mixture of earth-abundant MoO3 and NaCl as the solid precursors (see details in Supplementary Materials). Firstly, MoOxCy arrays were directly grown on carbon cloth substrates in a non-equilibrium hydrogen plasma environment within 20 min, denoted as HP-MoOC. During the growth process, the mixture of MoO3 and NaCl powders were introduced in the upstream of the substrates inside the tube (Figure ) to generate volatile metal oxychlorides (i.e., MoO2Cl2) at elevated temperatures as the metal precursor :