In situ growth of gold nanoparticles onto polydopamine-modified MXene to quickly and efficiently degrade dyes

As a typical two-dimensional MXene material with abundant oxygen-containing functional groups, Ti 3 C 2 could be used as an excellent carrier for noble metal nanoparticles to effectively avoid its agglomeration. However, Ti 3 C 2 was easily oxidized and deteriorated when stored in a conventional environment, so polydopamine (PDA) was used to modify Ti 3 C 2 to promote uniform loading of noble metal nanoparticles. Based on this, with Ti 3 AlC 2 as the raw material and PDA as the modifier, in situ growth of gold nanoparticles was carried out using chloroauric acid trihydrate as the precursor, and the target nanocomposite catalyst (Au@P-Ti 3 C 2 ) was then obtained. A sequence of characterizations were employed to analyze chemical structure of the resulting catalyst. The catalytic degradation performances of Au@P-Ti 3 C 2 toward amaranth, methylene blue, chrome black T, and Congo red were systematically investigated, and the results showed that catalytic degradation percentage of Au@P-Ti 3 C 2 for the above dyes could reach 100%. The pseudo-first-order kinetic model could be used to simulate the catalytic reaction process well, and catalytic reaction rate constants of Au@P-Ti 3 C 2 (2) for the four pollutants were 0.0411 s −1 , 0.0721 s −1 , 0.0273 s −1 , and 0.0105 s −1 , respectively. After 10 cycles of repeated catalysis, catalytic degradation percentage of the composite catalyst toward the four dyes could still remain above 89%. Therefore, this novel, green, and simple method to synthesize Ti 3 C 2 -based composite catalyst might provide extremely valuable application prospect for MXene-based catalyst in the field of harmless treatment of industrial dyes. Graphical Abstract