Wang Han,Li Haiying,Li Shouchun,Liu Li,Wang Lianyuan,Guo Xuexin
Biomorphic In 2 O 3 –ZnO hollow microtubules were synthesized by using cotton as template and followed by calcination. This environmental-friendly method using biomaterials as templates can be used to synthesize metal oxide semiconductor materials with specific morphologies. The structural and microscopy characterization were carried out with X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy. The SEM images display the porous structure of the as-obtained hollow microtubules, which is beneficial to increase gas sensing properties of materials. Gas sensors based on In 2 O 3 -doped ZnO hollow microtubules were investigated and the test results demonstrate the excellent acetone sensing properties of such porous materials. The response of In 2 O 3 –ZnO hollow microtubule sensors to 100 ppm acetone at the optimum temperature of 300 °C is 62.5, meanwhile the response and recovery times are 3 and 7 s, respectively. Moreover, even at 0.1 ppm of acetone detectable response can be observed, and the value is 2.82. At the same time the sensors have selectivity to acetone.
Biomorphic nano-hydroxyapatite (HAP) was fabricated by a co-precipitation method using cotton as bio-templates and employed in adsorptive removal of ofloxacin (OFL) and triclosan (TCS) that are two representative pharmaceuticals and personal care products (PPCPs). The surface area and porosity, crystal phase, functional group, morphology and micro-structure of the synthesized HAP were characterized by Brunauer–Emmett–Teller isotherm, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron macroscopic and transmission electron microscopy. The effects of initial pH, ionic strength, initial concentration, contact time and temperature on the removal of PPCPs were studied in a batch experiment. The adsorption of OFL and TCS was rapid and almost accomplished within 50 min. Kinetic studies indicated that the adsorption process of OFL and TCS followed the pseudo-first-order and pseudo-second-order models, respectively. The Freundlich isotherm described the OFL adsorption process well but the adsorption of TCS fitted the Langmuir isotherm better. Thermodynamics and isotherm parameters suggested that both OFL and TCS adsorption were feasible and spontaneous. Hydrogen bond and Lewis acid–base reaction may be the dominating adsorption mechanism of OFL and TCS, respectively. Compared to other adsorbents, biomorphic HAP is environmentally friendly and has the advantages of high adsorption capacity, exhibiting potential application for PPCPs removal.