Response to Comment on 'Platinized WO_3 as an Environmental Photocatalyst that Generates OH Radicals under Visible Light'

摘要

We write in response to the comments from Leng1 on our recent paper concerning the generation of OH radicals from platinized WO_3 under visible light and their role in the photocatalytic degradation reactions of aquatic pollutants.2 Leng raised three issues and our replies are as follows. We used Fe + ions as an alternative electron scavenger (instead of O_2) in a chemical trap experiment for OH radicals, observed that the absence of O_2 (but in the presence of Fe3+ as an electron acceptor) led to the marked inhibition of OH radical generation, and concluded that the generation of OH radicals through the oxidative path (reaction 1) should be minor. Leng claimed that Fe2+, which is generated by the reduction of Fe3+, should adsorb on the WO_3 surface and compete for valence band (VB) holes (reaction 2) with greatly inhibiting the production of OH radicals. Based on this reasoning, Leng claimed our conclusion is invalid.