Semiconductor-based photocatalytic hydrogen evolution from water with earth-abundant and low cost co-catalysts has attracted much attention. Herein, novel Cu2(OH)2CO3 decorated 2D TiO2 nanosheets for photocatalytic water splitting were synthesized by a facile in situ synthetic method. The chemical and photophysical properties of Cu2(OH)2CO3/TiO2 nanosheets were investigated by X-ray diffractometry (XRD), transmission electron microscopy (TEM), UV-vis diffusion reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) analysis. At an optimal Cu2(OH)2CO3 loading content of 1.5 mol%, the hybrid photocatalyst delivers a high photocatalytic H2 production rate of 1555.07 μmol g−1 h−1. Such enhanced photocatalytic activity is attributed to tight interfaces formed between Cu2(OH)2CO3 nanoparticles and TiO2 nanosheets, which play a vital role in the separation of photo-excited carriers, and the formation of active Cu1+ and Cu0 species can also benefit the charge separation process by reducing the over-potential of water reduction. Based on the above results, a possible mechanism is proposed and further verified using photoluminescence (PL) spectra. This work may provide more insight into the synthesis of novel Cu2(OH)2CO3/TiO2 nanosheets with high photocatalytic H2 evolution activity for solar-to-chemical conversion and utilization.
Chan Gao,Deshuai Zhen,Ni He,Zhengbin An,Qiulan Zhou,Chenyi Li,Craig A. Grimes,Qingyun Cai
High surface area (136 m 2 g −1 ) nanoporous two-dimensional TiO 2 nanoflakes are applied as an adsorbent and meanwhile a matrix for toxic small molecule analysis using positive-ion surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). The TiO 2 nanoflakes enable one-step enrichment and analysis, greatly simplifying the analysis technique. Due to the high enrichment efficiency and low background noise, small molecule organic contaminants at ppt or even sub-ppt concentrations such as malachite green (10 pg/mL), leucomalachite green (10 pg/mL), cetyltrimethylammonium bromide (0.001 pg/mL), rhodamine B (0.001 pg/mL), and crystal violet (0.1 pg/mL) were detected. In addition, malachite green and its metabolite leucomalachite green at ng/mL concentrations were successfully detected from fish blood and fish extracts, and crystal violet and its homologues at ng/cm 2 concentrations were detected from inks on thermal receipt papers obtained from local supermarket.
危险品化学品经营许可证（带存储）