Protonated NH2-MIL-125 via HCl vapor to introduce the moiety with charge and ample hydrogen as a novel bifunctional photocatalyst: Enhanced photocatalytic H2 production and NO purification

A novel protonated NH 2 -MIL-125 was fabricated to introduce the moiety with charge and ample hydrogen (–NH 3 + Cl - group) into NH 2 -MIL-125 using HCl vapor obtained by natural volatilization of hydrochloric acid as a protonating reagent, which could exhibit excellent photocatalytic activity in both hydrogen production and NO purification under visible light irradiation. The hydrogen production and NO purification rate of the best protonated NH 2 -MIL-125 were 6762.80 μmol g −1 and 49.17%, respectively, which were 20.53 and 1.84 times as that of the original NH 2 -MIL-125. A series of characterizations, such as Mott-Schottky, PL, FT-IR and in situ DRIFTS , etc. were used to characterize the photoelectrochemical properties of the optimal catalyst, which demonstrated the protonation effect can not only enhance the electron migration rate, but also effectively accelerate photo-generated electron-hole pairs separation in the photocatalytic reaction process. This research believed that using HCl vapor as a facile protonation reagent to introduce the moiety with charge and ample hydrogen (–NH 3 + Cl - ) was a very effective method to decorate MOFs for hydrogen evolution and NO removal.