Solvothermal Calcination Process Research Articles

Excellent triethylamine (TEA) chemiresistor based on ZIF-8 derived Ag sensitized ZnWO4/ZnO branched heterostructure for indoor environment

The detection of triethyl amine is necessary for environmental and human health concerns. However, sensitivity and selectivity are still challenges for real-time applications. Herein, ultrasensitive ZIF-8-derived Ag-sensitized ZnWO4/ZnO branched heterostructures were synthesized via a solvothermal-calcination process. The surface morphological investigation confirmed that ZnWO4 nanorods randomly grown on 3D whiskers of ZnO and Ag nanoparticles are decorated, which enhanced the sensing performance by synergistic effect. The Ag@ZnWO4/ZnO sensor exhibited 56.15 sensor response towards 5 ppm of TEA at 80 °C, which is 3.86, 3.14, and 1.83 times over from ZIF-8, ZnO, and ZnWO4 sensors respectively. Additionally, the sensitivity of Ag@ZnWO4/ZnO sensors for 1–5 ppm and 5–35 ppm range were found to be 11.96 and 13.78 response/ppm, respectively also, calculated limit of detection is 43 ppb earned.Furthermore, the fabricated sensor showed reliable consistency, outstanding repeatability, and stability. The surface area of branched heterostructure is high (83.39 g/cm2) which enhances the interaction between TEA molecules to thesensing surface. Furthermore, thedecoration of Ag nanoparticles is sensitized to a sensor and enhances the sensing performance.

Synthesis of Co-doped CeO2 nanoflower: Enhanced adsorption and degradation performance toward tetracycline in Fenton-like reaction

In Fenton-like reaction, adsorption and degradation are inseparable processes. The pollutants were enriched on the surface of catalyst by adsorption leading to the increase of the local concentration, and this was beneficial for acceleration of the degradation rate. Therefore, a catalyst with high adsorption capacity, low metal leaching and rapid activation rate toward peroxymonosulfate (PMS) was highly desirable. In this paper, Co-doped CeO2 (Co-CeO2) nanoflower was prepared via a solvothermal-calcination process. The nanoflower with a hierarchical porous structure was made up of dozens of nanosheets. Compared to CeO2, more Ce(Ⅲ) sites and defects were generated on Co-CeO2 surface, and the maximum adsorption capacity was increased by 1.92 times. Benefiting from the high activity of Co toward the activation of PMS, the degradation rate was enhanced 6.7 times. The major radicals were determined and the corresponding degradation mechanism was revealed. Additionally, Co-CeO2 nanoflower was demonstrated to be high efficient in many persistent organic pollutant degradation and also exhibited outstanding reusability after several cycles. Moreover, the leaching of toxic Co ions was 12 times lower than the referenced Co3O4. This work provides a promising approach on rational design a catalyst with high adsorption property and degradation efficiency in Fenton-like reaction for environmental remediation.

Fabrication and characterization of I doped Bi2MoO6 microspheres with distinct performance for removing antibiotics and Cr(VI) under visible light illumination

A solvothermal-calcination process was applied to fabricate a series of novel I doped Bi2MoO6 microspheres. The obtained Ix-Bi2MoO6 microspheres presented outstanding photocatalytic activity for removal of three antibiotics (Tetracycline-TC, ciprofloxacin-CPFX, oxytetracycline hydrochloride-OTTCH) and Cr(VI) under visible-light illumination. The texture and physicochemical properties were investigated by XRD, SEM, TEM, XPS, UV–vis DRS and photo- electrochemical test. After iodine doping, the specific surface area of Bi2MoO6 was obviously increased, which contributed to the enhanced adsorption for antibiotics and Cr6+ in water. In addition, I0.4-Bi2MoO6 (theoretic molar ratio of I to Mo is 0.4) exhibited the highest photocatalytic activity. And after visible-light illumination for 3 h, the removal rates are 88.8%, 90.0% and 89.6% for TC, CPFX, and OTTCH, respectively. Moreover, I0.4-Bi2MoO6 possesses the distinct activity for removing Cr(VI) in water.

Binary-phase TiO2 modified Bi2MoO6 crystal for effective removal of antibiotics under visible light illumination

A series of binary-phase TiO2 modified Bi2MoO6 nanocrystals have been prepared via a solvothermal-calcination process. Trace TiO2 modification can effectively enhance the visible light catalytic activity of Bi2MoO6 to remove the antibiotics in aqueous solution. The obtained TiO2/Bi2MoO6 composites were investigated by some physicochemical techniques like XRD, N2 adsorption, SEM, TEM, UV–vis DRS, Raman, XPS, PL and Photo-electrochemical measurement. The presence of TiO2 nanoparticles (NPs) influenced the crystal growth of Bi2MoO6, decreasing the crystal size of Bi2MoO6 and effectively promoting its specific surface area. Moreover, the conduction band of TiO2 can serve as the electron transfer platform, which largely boosts the effective separation of photocarriers at TiO2/Bi2MoO6 heterojunction interface. With optimal TiO2 content (0.41 wt%), TiO2/Bi2MoO6 exhibited the best photocatalytic performance for different antibiotics degradation, e.g. ciprofloxacin, tetracycline and oxytetracyline hydrochloride under visible light irradiation. Moreover, the mechanism for enhanced photocatalytic performance in ciprofloxacin degradation was illuminated.

Influence of Calcination Temperature on Particle Size and Photocatalytic Activity of Nanosized NiO Powder

Nanosized NiO particles were synthesized by a combined solvothermal-calcination process using Ni(NO3)2 · 6H2O as a starting reagent in the presence of ethylene glycol. The effect of varying the calcination temperature from 500 to 700°C on crystallinity and particle size of the synthesized NiO nanoparticles was investigated. The crystallinity and particle size of the NiO nanoparticles increased with increasing calcination temperatures. The particle size–photocatalytic activity relationship of the synthesized NiO nanoparticles was investigated. It was found that the NiO with smaller particle size and larger surface area shows strong UV–Vis absorption. The NiO nanoparticles calcined at 500°C degraded Congo red under the xenon light better than those calcined at higher temperatures.

Novel fluorinated Bi2MoO6 nanocrystals for efficient photocatalytic removal of water organic pollutants under different light source illumination

Development of efficient technologies to deal with organic pollutants in wastewater is an important issue. Photocatalysis, as a “green chemistry” technology, has attracted much attention in pollutants degradation and efficient visible-light-driven photocatalysts with powerful ability to completely oxidize organic pollutants in contaminated source water are highly desirable. Here, a series of fluorinated Bi2MoO6 crystals with different atomic ratio of F to Bi (RF=0.10, 0.15, 0.20, 0.25, 0.30) were prepared via a solvothermal-calcination process. The effects of F doping on the physicochemical properties of Bi2MoO6 were investigated by physicochemical techniques like XRD, N2 adsorption, SEM, TEM, UV–Vis DRS, FT-IR, XPS, PL and photoelectrochemical measurement. The substitution of F− anions for the host O2− anions induced the lattice shrinkage, a decrease in crystal size and an increase in crystallinity. Moreover, the oxygen vacancies in F-Bi2MoO6 and F− adsorbed over the catalyst surface could withdraw the photoexcited electrons, largely boosting the separation of photoexcited electron–hole pairs. F0.20-Bi2MoO6 displayed significant photocatalytic performance in removal of phenol, bisphenol A, 4-chlorophenol and Rhodamine B dye. ESR and radicals trapping confirmed holes are mainly responsible for the degradation of the target organic pollutants. However, •OH and •O22− could be also involve in photocatalytic reactions. Meanwhile, the more positive potential of VB in F-Bi2MoO6 could promote the oxidation power of the h+ in organic pollutants removal.

Catalytic behavior of silver/alumina prepared by solvothermal calcination process for the selective reduction of nitric oxide with butane

Ag/g-Al 2 O 3 with a high activity for the selective reduction of NO with butane in the presence of oxygen was synthesized by the solvothermal-calcination process. The activity was superior to that prepared by the impregnation-calcination process, probably due to the relatively higher amount of the well dispersed active Ag + and some Ag n d+ clusters in the SC catalyst.