Enhanced visible light photocatalytic activity of Cu-doped SnO2 quantum dots by solution combustion synthesis

Copper (Cu)-doped tin oxide (SnO2) quantum dots (QDs) were prepared using energy-efficient solution combustion synthesis. The synthesized nanoparticles were characterized by XRD, TEM, XPS, UV-Vis DRS, and FT-IR. The X- ray diffraction (XRD) pattern shows that the QDs have tetragonal rutile-like structure. HR-TEM shows modification in the growth inhibition of the SnO2 lattice parameters with Cu doping. When increasing the Cu concentration, the optical band gap energy of SnO2 decreases. X-ray photoelectron spectroscopy (XPS) reveals the presence of copper and tin as Cu(2+)and Sn4+, respectively. Fourier transform infrared (FT-IR) spectroscopy confirmed the fundamental vibrational modes of SnO2. The photocatalytic degradation of methyl orange dye was measured under visible light irradiation using the QDs as catalysts. The QDs with 0.03 mol % Cu doping showed the highest photocatalytic performance with 99% degradation of the dye under visible light within 180 min, which means they could be used to treat polluted water.clos

Bio-based liquid fuels as a source of renewable energy: A review

Limited availability of fossil fuels and their associated environmental impact during combustion remains the primary basis for exploring alternative energy sources such as bio-based liquid fuels. Several feedstocks have been used to produce biofuels for different applications with their own pros and cons. For instance, production of bio-fuels using human food chain raw materials such as corn, soy, peanut, and sugarcane are receiving increased criticism due to the competing demands of the same sources for human consumption as food. However, the non-food biomass in the form of agricultural wastes, municipal wastes, waste vegetable oil, and microbial sources are abundantly available that can be utilized as feedstock for production of biofuels. Because of this reason, most biofuels have been produced using the feedstocks that do not affect the food chain. Thus, in this work, the feedstocks of different generation biofuels and their potential yield and associated greenhouse gas emissions, production technologies are critically surveyed. Moreover, the application of biofuels for different purposes are analyzed and compared with their corresponding conventional fuels. The survey also points out the recent issues and challenges of biofuels with their resolution. The future research directions are suggested to sustain biofuel production