In this paper, the photocatalytic activity of nitrogen-doped TiO2/montmorillonite composite (NTM) was successfully enhanced by modification with carbon. NTM was made by mixing a swelling clay solution with an N-doped TiO2 solution prepared by hydrolysis of titanium tetraisopropoxide with urea. Carbon-modified N-doped TiO2/montmorillonite composite (CNTM) was obtained by grinding the dried NTM with EtOH for 1 h, followed by calcination at 250°C in the air for 2 h. Both NTM and CNTM exhibited visible light absorption in the UV–vis spectrum in the same way as commercial N–TiO2 powder. Additionally, CNTM greatly extended the absorption edges to the visible light region. The photocatalytic performance of NTM and CNTM was evaluated using a degradation of bisphenol-A under visible light (>420 nm) radiation. Although the commercial TiO2 powder showed less photocatalytic activity under visible light radiation, NTM, CNTM and commercial N–TiO2 powder showed high photocatalytic activity. The order of degradation performance was as follows: CNTM > commercial N–TiO2 powder > NTM. Since the TiO2 content of CNTM is ca. 30 mass % by energy dispersive spectrum analysis, it was suggested that CNTM has extremely high visible light activity.
This work describes that the photocatalytic activity of microsized TiO2 fibers for degrading gaseous acetaldehyde can be systematically enhanced by introducing nanostructured interior hollow channels, which is achieved by a facile multifluidic electrospinning method. The increased channel number augments the BET surface area of TiO2 fibers intuitively. A quite interesting phenomenon is that the percentage increase for photocatalytic activity is higher than that for surface area. It is thus proposed that the multichannel hollow structures induce not only an inner trap effect on gaseous molecules, but also a multiple-reflection effect on incident light, which further improves the photocatalytic activity of TiO2 hollow fibers.
A fabrication process for superhydrophilic-superhydrophilic patterns on titanium substrates prepared through a combination of an ink-jet technique and site-selective decomposition of a self-assembled monolayer (SAM) by a TiO(2) photocatalyst under UV irradiation is described. We demonstrate that the prepared titanium substrate is applicable as an offset printing plate with high resolution (133 and 150 lines per inch). Furthermore, the superhydrophilic-superhydrophobic patterns on the substrate can be deposited repeatedly after elimination of the patterns by photocatalytic decomposition of TiO(2) under UV irradiation. A second printed image with the renewed substrate showed no significant difference in image quality compared with the initial image.
Abstract The effect of cation substitution into CaTiO3 has been investigated. Rh-doped CaTiO3 showed intense absorption in the visible light region (λ > 420 nm), and was found to be a new photocatalyst for H2 evolution from an aqueous methanol solution under visible light irradiation.
