Degradation of formaldehyde and methylene blue using wood-templated biomimetic TiO2

Abstract

The multilevel pore structure of natural wood is an ideal template material for the synthesis of functional materials. In this study, a natural wood pore structure was introduced into the structure of titanium dioxide through a biological template synthetic strategy. The resulting structure showed improvement in the adsorption of formaldehyde and methylene blue from solution. It also manifested excellent photocatalytic performance under visible light. The results of photocatalytic degradation illustrated that wood-templated titanium dioxide degraded 71.8% of the formaldehyde in solution within 100 min under visible light. In addition, the efficiency of methylene blue (MB) degradation was as high as 97.9% within 60 min. The morphology and structure of titanium dioxide were characterized by SEM, TEM and X-ray diffraction. This revealed that the crystalline phases of the prepared titanium dioxide were anatase and rutile, and rutile titanium dioxide was attached to the surface of anatase titanium dioxide. Compared with TiO2 without a wood template, TiO2 prepared with a wood template showed an obvious absorption redshift in the visible light region, which significantly increased absorption. The binding energy of Ti ions in TiO2 with a wood template changed, and Ti3+ ions were produced. Due to the existence of more oxygen vacancies, the photocatalytic activity of TiO2 made with a wood template improved. The multiscale pore structure of TiO2 inherited from the wood template played a key role in developing the visible-light photocatalyst.