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Research Subject: The conversion of anthropogenous CO₂ gas into value-add chemicals known as solar fuel technology attracted much consideration from the beginning of the 21st century owing to the potential of this technology in solving the climate change and energy shortage issues.
Research Approach: In the current study, Bismuth and copper modified TiO₂ were prepared using sol-gel and wet impregnation method in order to investigate as a catalyst for photocatalytic conversion of carbon dioxide into renewable methane.  
Main Results: The results of X-ray diffraction analysis, Field emission scanning microscope images and Transmission electron microscope images demonstrated that titanium dioxide nanoparticles with 20 nm in size were synthesized that after the addition of bismuth, the size of particles became smaller. Also, using energy dispersive x-ray analysis and elemental mapping technique, it was determined that the bismuth and copper were uniformly inserted in the prepared nanoparticles. Diffuse reflectance spectroscopy showed that the bandgap became smaller in bismuth and copper-containing samples, which resulted in visible light absorption. In addition, photoluminescence spectroscopy showed an impressive decrease in the rate of electron-hole separation in the prepared nanocomposite. The result of CO₂ photoreduction experiments revealed that the incorporation of 3 wt% Bismuth and 1.5 wt% copper into the structure of TiO₂ would increase the amount of methane production to 7.6 times greater than bare TiO₂. This superior activity for methane generation could be related to the ability of bismuth compounds in adsorption and activation of carbon dioxide molecules and also the efficient separation of charge carriers given by copper. Additionally, the smaller particle size and increase in the surface area had also a positive effect on the CO₂ reduction enhancement.

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Research subject: Osmosis membrane bioreactor is one of the best industrial wastewater treatment methods. The main advantage of using osmosis process is its operation at low hydraulic pressures which has a better performance in removing pollutants and low energy consumption than other methods                        
Research approach: In this research, Nano porous Titanium dioxide powder with a specific surface area and anatase wall was synthesized through a thermal process using cetyltrimethylammonium bromide (CTAB) as a surfactant directing agent and a pore-creating agent.Ultrafiltration nanocomposite membranes were made using modified titanium dioxide (TiO₂) (MT) and polysulfone (PSf) by phase the inversion method. The morphology and structure of the prepared membranes and nanoparticles were investigated using by atomic fourier transforms infrared spectroscopy(FESEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). In this research, bovine serum albumin (BSA) was used as simulated wastewater for the feed solution. The fabricated ultrafiltration membranes were tested in osmosis membrane bioreactor (OMBR) system due to lower energy and fouling. 0.6 % solution of poly (sodium 4-styrene sulfonate) was used as an osmotic solution. Comparative separation performance and antifouling properties of both nanocomposites in several analyzes such as water contact angle measurement, pure water flux and filtration of different concentrations of bovine serum albumin solution. BSA and fouling resistance have been investigated


Main results:  TThe results that Due to the addition of MT nanoparticles to the polymer matrix, the hydrophilicity and surface energy of the membrane increased, which led to the improvement of the membrane performance. The membrane containing 1% titanium oxide nanoparticles showed the best result. For example, for feeding with a concentration of 200 ppm, the water flux increased from 20 to 38.5 L/ m² h, and the percentage of returning lethal solution decreased from 19.6 to 30 g/ m² h. The flux recovery in this membrane was 96%, which indicates the antifouling property of the modified nanocomposite membrane.                                                                
              

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Nanofluids are engineered by suspending nanoparticles with average sizes below 100 nm in traditional. The ever increasing of thermal loads in such applications requires advanced operational fluid characteristics, for example, high thermal conductivity dielectric oils in transformers and car radiators. These fluids require high thermal conduction, as long as electrical insulation. In the present work the thermophysical and rheological properties of the nanofluids such as thermal conductivity, viscosity and density are obtained from molecular dynamics simulations. These results served as initial data for computational fluid dynamics simulations to calculate heat transfer coefficient. The results show that, adding titanium oxide nanosheet in the base fluid enhanced the thermal conductivity and increased the viscosity and density of the base fluid. The theoretical calculations are confirmed the molecular dynamics simulation results and the simulation methods accuracy. The computational fluid dynamics results show that increasing the amount of titanium oxide nanosheet in the base fluid increases the heat transfer coefficient and increasing ethylene glycol ratio in base fluid leads to lower heat transfer coefficient. Also non-equilibirium molecular dynamics method can use as a effective and accurate method for nanofluids investigation. The coding which used to obtaine the thermal conductivity of nanofluid is a novel and modified type of non-equlibiruim molecular dynamics method. With using this coding the eror persentages of simulations is decreases. The other advantage of this code is reducing the simulation process, becous the molecular dynamics simulations need a long time for processing.

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Edible films, which in addition to creating beneficial effects by carrying antimicrobial compounds, antioxidants, etc., have biodegradable properties, have attracted the attention of many researchers. In this study, the gum obtained from the inner pod of bean with two concentrations of glycerol (40 and 60%) and three concentration of oregano essential (1, 2 and 3%) oil was used to produce biofilms. After studying the physicochemical and mechanical properties of the resulting films, the best treatment was combined with titanium oxide nanoparticles in two concentrations of 1 and 2% and its antimicrobial properties were also investigated. The results showed that increasing the essential oil raised the film thickness, while high concentrations of essential oil decreased the moisture content of the films. Although the addition of essential oil reduced the solubility of films compared with control sample, but in the treatments with essential oil, increasing the essential oil reduced the solubility of the film. Increasing the concentration of essential oil also increased turbidity and free radical DPPH activity. High concentrations of essential oil decreased the lightness of the films but increased the yellowing and redness compared to the control sample. Due to the interaction of the oil in the essential oil with the gum, the cohesion of the polymer network decreased and consequently, the tensile strength and the elongation factor at the break point decreased. Antimicrobial effect of films with 3% essential oil and 2% titanium oxide had the highest inhibitory area in the disk diffusion test with other samples on Staphylococcus Aureus, Escherichia coli, Salmonella Typhoid, Bacillus Cereus and pseudomonas Aeruginosa significantly (p<0.05)