Adsorption experiments Of the samples, 5 mg was re-dispersed in 10 mL of the organic dyes (concentration 10 mg/L) and the mixed solution was stored in the dark for 45 min with gentle stirring. The reaction solution was sampled every 15-min intervals at room temperature; 2 mL solution was sampled and centrifuged to remove the adsorbents, and the corresponding UV-visible

spectra were recorded to monitor the progress of the degradation of organic dyes by a Shimadzu 2550 UV-visible spectrophotometer. Results and discussion Figure 1a shows the representative XRD patterns of the as-obtained hollow SnO2 and hollow SnO2@C nanoparticles. All of the diffraction peaks can be well indexed to the tetragonal rutile phase of SnO2 (JCPDS card No. 41-1445). The absence of characteristic

peaks corresponding to impurities selleck kinase inhibitor indicates high purity of the products [17]. The result reveals that the carbon coating process and annealing treatment will not change the structure of the SnO2. To prove the generation of the carbon layer on the as-prepared hollow SnO2 seeds, the two samples were characterized by Raman spectroscopy. As shown in Figure 1b, the two peaks of 1,585 and 1,360 cm−1 can be observed in the hollow SnO2@C sample, which can be attributed to the E2g vibration mode of the ordered carbon layer (G band) and the A1g vibration mode of the disordered carbon BMS-907351 cost layer (D band), PR-171 ic50 respectively. The peak intensity ratio (I D/I G) (ca. 0.76) calculated is a useful index for comparing the degree of crystallinity of various carbon materials; a smaller value ratio reflects a higher degree of check details ordering in the carbon material. The peaks at 560 and 629 cm−1 can be observed, respectively. The peak at 560 cm−1 can be assigned to the Sn-O surface vibrations; the peak at 629 cm−1 can be indexed to the A1g mode of SnO2. The above results reveal that the carbon has been successfully coated on the surface of the SnO2 nanoparticles, and the structure of SnO2 was not change. Figure 1 XRD patterns (a) and Raman

spectra (b) of the as-obtained hollow SnO 2 and hollow SnO 2 @C nanoparticles. The structure and morphology of the as-prepared hollow SnO2 nanoparticles are investigated by TEM and HRTEM. As shown in Figure 2a, the as-prepared samples mainly consist of uniform flower-like nanoparticles. The contrast (dark/bright) between the boundary and the center of the nanoparticles confirms their hollow nature. The histogram of the particle diameters (inset in Figure 2a) demonstrates that the average diameter of the as-prepared hollow SnO2 nanoparticles is 53 nm. The bright rings in the selected-area electron diffraction (SAED) pattern (Figure 2b) can be well indexed to the rutile-phase SnO2. Figure 2c shows the TEM image at high magnification of the hollow SnO2 nanoparticles.