In this research, an experiment was conducted by introducing superhydrophobic surface into rolling spheronization granulation. The employed superhydrophobic surface was prepared with modification of an anodized Cu mesh with silane FAS-17 and exhibited excellent uniformity, adequate stability, and broad adaptability in the granulation scenario. Completely spherical molecular sieve granules with 99.85% sphericity and 2.53 mm diameter were obtained. The compressive strength of a single granule reached 7.402 N/ea. Only negligible residual mass and slight surface abrasion were observed in the granulation process. Force analysis confirmed that the staged motion behavior of droplets caused by the interaction between the slurry and the superhydrophobic surface benefited to the formation of spherical granules. Successful application of this process for granulation of other substances confirmed its wide suitability. With the advantages of easy fabrication, high-quality granules, and low cost, rolling-spheronization granulation on superhydrophobic surfaces has great potential for scale-up applications.

LiBr refrigerating systems are frequently used in industry, but the pipelines are easily corroded or blocked by the LiBr solution with high flow resistance. Here, a superhydrophobic Fe surface was proposed and tested for applicability. After constructing a rough Fe2O3 nanotube array on a Fe surface by the anodization process, a superhydrophobic Fe surface was obtained by silane modification. The as-prepared superhydrophobic surface exhibited excellent repulsion to LiBr solutions. The modified Fe foil showed a 3.35% decrease in thermal conductivity but a 99.2% improvement of anticorrosion protection efficiency. LiBr crystals deposited on this surface were easily detached. The flow resistance along the superhydrophobic surface was reduced to 50% of that along a pure Fe surface. The operation temperature of the system was broadened due to low blockage risk. The excellent thermal conductivity, anticorrosivity, drag reduction, and antifouling performance of the superhydrophobic Fe surface exhibits promise for industrial application.

A microchannel reactor is a promising reactor type for industrial applications. However, loading heterogeneous catalysts in the microchannels is troublesome because of the high pressure drop and serious fluid flow abrasion. In this research, a home-made microchannel reactor was designed by using a wall-loaded Pt/TiO2/Ti catalyst as the microchannel wall. This wall-loaded Pt/TiO2/Ti catalyst was prepared by anodizing a Ti foil and photodepositing Pt on the anodic surface layer. The foil was then assembled as a side wall of the microchannel. Ammonia oxidation was used as the probe reaction for evaluating the performance of this microchannel reactor by using the wall-loaded catalyst. Simulation and experimental results show that 100% ammonia conversion can be obtained under the following conditions: temperature, 300 °C; gaseous hourly space velocity, 35000 h−1; catalyst loading percentage, 85% of the total channel area; and ammonia to oxygen volume ratio, 1:13, in the absence of nitrogen, with a microchannel of length 80 mm, width 1.0 mm, and height 0.3 mm. Pressure drop in the microchannel is as small as 1.18 kPa, and temperature distribution is relatively uniform. Notably, NOx selectivity is significantly improved to become 88.32% at 300 °C. Simulations confirm that the selectivity showed such a high improvement owing to the short residence time of NOx because of the unique blind-hole structure of TiO2 nanotubes and the resulting large mass transfer resistance. The operation of this reactor with the wall-loaded Pt/TiO2/Ti catalyst is stable without any remarkable performance decay even after 360 h of operation. Hence, the microchannel reactor with a wall-loaded catalyst on the anodic metal is an attractive prospect for large-scale applications of rapid gas-to-solid exothermic reactions.

Anodized TiO2 nanotube array (TNA) is a promising material which has attracted wide attentions but its presumed growth mechanism remains enigmatic yet. In this research, Density Functional Theory (DFT) was applied to determine the growth mechanism of TNA on the surface of titanium foil. The firstprinciples within the generalized gradient approximation (GGA) and Perdew-Burke-Emzerhof (PBE) exchange-correlation function based on the density functional theory was employed to calculate anodization process on anatase TiO2 (001) surface. Calculation results indicated that the chain reaction model for multimolecular HF destructive adsorption on surface of TiO2 layer was the key step of anodization to form the initial defects. The HF molecule inclined to adsorb on the defective site owing to the low adsorption energy, resulting in the successive corrosion to deepen the defect and finally to form the nanotube. Complex ion [TiF6]2– can be formed in electrolyte by interaction with 5c-Ti and F- in this corrosion process. This theoretically calculation confirms the growth mechanism hypothesis of TNA.

Ag2S has only rarely been investigated as a photocatalyst on its own, although it has been widely used as an important component of composite photocatalysts. We synthesized Ag2S by a facile ion-exchange method at room temperature and used it directly as an effective photocatalyst. Our results confirmed the excellent performance of Ag2S in completely photodegrading methyl orange within 30 min under irradiation with visible light and within 70 min under irradiation with near-infrared light. This good performance is ascribed to the narrow band gap (1.078 eV) of Ag2S and the lower recombination efficiency of the photogenerated electron–hole pairs of Ag2S in the photocatalytic process. The active species in the photo-oxidation process was identified as anioic ozone radicals. This simple preparation method and high photocatalytic performance increases the possible future applications of Ag2S.

Photocatalytic processes are an environmentally friendly technology for treatment of persistent organic pollutants. However, the majority of current photocatalysts cannot utilize sunlight sufficiently to realize fast decomposition of organic pollutants. In this research, a silver oxide nanoparticle aggregation with superb photocatalytic performance under artificial light source and sunlight was prepared and characterized. The results showed that methyl orange (MO) was decomposed completely in 120 s under irradiation of artificial visible light, artificial ultraviolet light, and sunlight, and in 40 min under near-infrared (NIR) light. The superb photocatalytic performance of as-prepared silver oxide remained almost constant after reuse or exposure under sunlight. It was confirmed that the co-working effect of photogenerated hole and ozone anion radicals did play an important role in the process of MO photodegradation with the existence of Ag2O. The narrow band gap of Ag2O, less than 1.3 eV, resulted in the photocatalytic performance of Ag2O under NIR light. Furthermore, the high surface area and numerous crystal boundaries provided by the aggregation of Ag2O nanoparticles efficiently increased the escape probability of photogenerated electrons and the contact probability of photogenerated holes with outside materials, assuring superb photocatalytic activity and excellent stability of as-prepared Ag2O samples.

Antiscaling technology is necessary in order to prevent the performance loss and blockage of heat exchangers. In this research, a superhydrophobic CuO nanowire layer was prepared and utilized for antiscaling process of CaCO3 on the surface of copper. Modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS-17), the water contact angle on the CuO surface increased sharply from 4.5° ± 1° after anodization to 154° ± 2°, since the surface free energy decreased from 74.8 mJ/m2 for the hydrophilic surface to 0.2 mJ/m2 for the superhydrophobic surface. The scale inhibition performance of the surface of superhydrophobic CuO nanowires was confirmed since the corresponding scaling weight of deposited CaCO3 decreased significantly from 0.6322 mg/cm2 to 0.1607 mg/cm2. This attractive antiscaling effect of the modified superhydrophobic CuO nanowire surface should ascribe to the slow CaCO3 crystal nucleation rate, because of the low surface energy, low adhesion strength of CaCO3 crystal, and air film retained on the superhydrophobic surface.

In this work, hematite nanowire arrays (HNA) were fabricated on pure iron foil by using anodization process in fluoric electrolyte to produce superhydrophilic surfaces. The in situ growth of HNA on iron substrates was ascertained by scanning electron microscopy images, X-ray photoelectron spectroscopy and glancing angle X-ray diffraction measurements. The resultant HNA-bearing iron surfaces showed superhydrophilic property with a contact angle of 7 ± 2°, and its super-hydrophilicity remained longer than three days in air.

Biodiesel is a promising alternative biofuel, but the treatment of wastewater containing alkali catalyst and glycerol discharged from the washing unit operation increases the cost significantly. Here a novel continuous biodiesel production process with trace-amount alkali as the catalyst under the methanol subcritical condition was proposed and investigated. The optimal operation conditions of preliminary batch reaction experiment are temperature of 200 °C, catalyst concentration of 513 mg/kg, reaction time of 38 min, molar ratio of methanol to oil of 11.9:1, and system pressure of 1.5 MPa. The one-step conversion of raw oil in a batch reactor can reach up to 85.5%. The alkali residue in the biodiesel product can be further reduced by removing the methanol and washing by glycerol instead of by acid or water. The optimal weight ratio of glycerol to biodiesel is 1.5:1, and the residual alkali in the final ester product is about 4.6 mg/kg. The simulation and bench scale continuous experiment based on the optimal batch operation parameters confirmed that the biodiesel produced by the process is qualified well up to the Chinese standard of biodiesel, and the K+ concentration in biodiesel was less than 3.0 mg/kg. The economic evaluation showed that this new process is more economically feasible than the traditional processes.