Room‐Temperature Carbide‐Derived Carbon Synthesis by Electrochemical Etching of MAX Phases

Abstract Porous carbons are widely used in energy storage and gas separation applications, but their synthesis always involves high temperatures. Herein we electrochemically selectively extract, at ambient temperature, the metal atoms from the ternary layered carbides, Ti 3 AlC 2 , Ti 2 AlC and Ti 3 SiC 2 (MAX phases). The result is a predominantly amorphous carbide‐derived carbon, with a narrow distribution of micropores. The latter is produced by placing the carbides in HF, HCl or NaCl solutions and applying anodic potentials. The pores that form when Ti 3 AlC 2 is etched in dilute HF are around 0.5 nm in diameter. This approach forgoes energy‐intensive thermal treatments and presents a novel method for developing carbons with finely tuned pores for a variety of applications, such as supercapacitor, battery electrodes or CO 2 capture.