Theoretical design and experimental investigation on highly selective Pd particles decorated C3N4 for safe photocatalytic NO purification.

Rational design of highly active and selective photocatalyst for NO removal is significant for the commercial application of photocatalytic technology because the secondary byproduct caused by insufficient and non-selective pollutant oxidation process is a major challenge. In this work, Pd nanoparticles decorated C3N4 (PdCN) is designed by density functional theory (DFT) at first. The PdCN exhibits superiority to CN in terms of both kinetics and thermodynamics performances, as reflected in the lower activation barrier of rate-determining step and higher selectivity for the final product (nitrate) instead of toxic intermediate (NO2). The as-designed highly selective and efficient photocatalyst is then fabricated by a facile method with an extremely low content of Pd particles supported on C3N4. Compared to bare CN, the synthesized PdCN exhibits highly enhanced purification of NO in air and strong inhibition of toxic NO2 by-product as supported by in-situ DRIFTS investigation, which is consistent with the theoretical prediction. This work is a typical demonstration of setting up a bridge between theory and experiment to give a promising way to the rational design of advanced photocatalysts and atomic understanding of the reaction mechanism.