Hydrogen photochromism in V₂O₅ layers prepared by sol–gel technology with the use of dimethylformamide as a hydrogen donor

Here we report on the hydrogen photochromism carried out in the V₂O₅ xerogels with the use of dimethylformamide (DMF) as a hydrogen donor. The adsorption of DMF was carried out by an original method: DMF was adsorbed on the V₂O₅ surface along the formation of the xerogel from the sol containing the hydrogen donor. The mechanism of the DMF adsorption on the V₂O₅ xerogel surface has been discovered by Fourier transform infrared spectroscopy. DMF molecules have been bonded to the oxide surface by donor–acceptor and hydrogen bonds, which pre-determines easy detachment of hydrogen atoms under the action of light. It has been demonstrated that the pronounced hydrogen photocromism can be carried out in the V₂O₅ xerogels with the use of DMF. The peculiarities of the photochromism have been discussed. The spirit of the research is to provide charging of the V₂O₅ surface with the hydrogen donor along the formation of the oxide xerogel catalyst.