Investigation on the photocatalytic activity of chemically synthesized zirconium doped cadmium selenide nanoparticles for indigo carmine dye degradation under solar light irradiation

A simple chemical methodology has been adopted for the synthesis of zirconium (Zr) doped and un-doped cadmium selenide (CdSe) nanoparticles for the application towards photocatalytic degradation of indigo carmine (IC) dye under solar light irradiation. The as prepared Zr-CdSe (doped) and CdSe (un-doped) nanoparticles were characterized by ultraviolet visible spectroscopy (UV-vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX) and Transmission electron microscopy (TEM) studies. The inclusion of Zr ion into the CdSe nanoparticles matrix was confirmed by SEM-EDAX and XRD studies. TEM studies confirm the zirconium ions are uniformly doped over the CdSe surface. The photocatalytic degradation performance of Zr doped and un-doped CdSe nanoparticles were examined for the degradation of IC dye under solar light irradiation. The experimental results showed that the Zr doped CdSe possessed greater photocatalytic activity in comparison to un-doped CdSe. Photodegradation process parameters such as the initial concentration of the dye, as well as the amount of catalyst and time were investigated. The photocatalytic degradation rate was favored by a high concentration of solution in respect to Langmuir–Hinshelwood model

Biodiesel production from used cooking oil using a novel surface functionalised TiO2 nano-catalyst

A novel, efficient and recyclable mesoporous TiO2/PrSO3H solid acid nano-catalyst was synthesised by the post-synthetic grafting of propyl sulfonic acid groups onto a mixed phase of a TiO2 support. The synthesised nano-catalyst was characterised using FTIR, SEM, TEM, XPS, N2 adsorption–desorption isotherms, XRD, DSC, TGA, and CHNS analysis. The percentage of loading for propyl sulfonic acid on the TiO2 support was calculated using CHNS analysis and TGA. The catalytic performance of TiO2/PrSO3H on the production of the fatty acid methyl esters (FAME) via simultaneous esterification and transesterification reactions from used cooking oil (UCO) has been studied. The effects of different process parameters showed that 98.3% of FAME can be obtained after 9 hrs of reaction time with 1:15 molar ratio of oil to methanol, 60 °C reaction temperature and 4.5 wt% catalyst loading. It was also found that the one-pot post-surface functionalisation strategy with hydrophilic functional groups (-SO3H) enhanced the acid strengths of the nano-catalyst providing more acid sites for the reactants, and improving the accessibility of methanol to the triglycerides (TG)/free fatty acids (FFAs) by increasing the pore volumes/sizes of the nano-catalyst. The solid acid nano-catalyst was re-used in four consecutive runs without significant loss of catalytic efficiency. Finally, the synthesised biodiesel fuel satisfied ASTM and EN standards

Synthesis of Ti(SO4)O solid acid nano-catalyst and its application for biodiesel production from used cooking oil

A novel solid acid nano-catalyst [Ti(SO4)O] was synthesised and used for the simultaneous esterification and transesterification of free fatty acids in used cooking oil (UCO) to produce biodiesel. The synthesised nano-catalyst was fully characterized by different analytical techniques. The XPS results clearly confirmed that the bidentate sulphate coordinated to the Ti4+ metal in the nano-catalyst product. Obtained d-spacing values from the experimental data of XRD peaks and the SAED pattern of produced nano-catalyst agreed well with the d-spacing values from the JCPDS-ICDD card numbers 04-011-4951 for titanium sulphate oxide or titanium oxysulfate crystal structures.This confirms the sulphate groups were within the crystalline structure rather than on the surface of titania nanoparticles, which has not been previously reported. It has been demonstrated 97.1% yield for the fatty acid methyl ester can be achieved usign the synthetised catalyst under a reaction time of 3 h, catalyst to UCO ration of 1.5 wt% and methanol to UCO ratio of 9:1 at 75 °C reaction temperature. The nano-catalyst showed a good catalytic activity for the feedstock containing ≤6 wt% free fatty acid. Furthermore, the catalytic activity and re-usability of the Ti(SO4)O for the esterification/transesterification of UCO were investigated. XRD results confirmed that the amount of View the MathML source species in the solid acid nano-catalyst slowly decreased with re-use after 8 cycles under optimised conditions, which is higher than the reusability of other functionalised titania reported in the literature. Finally, the biodiesel prodcued from this process satisfied the ASTM and European Norm standards

Beneficial role of ZnO photocatalyst supported with porous activated carbon for the mineralization of alizarin cyanin green dye in aqueous solution

The present investigation depicts the development of a simple and low cost method for the removal of color from textile dyeing and printing wastewater using ZnO as photocatalyst supported with porous activated carbon (AC). Photocatalytic degradation studies were carried out for water soluble toxic alizarin cyanin green (ACG) dye in aqueous suspension along with activated carbon (AC) as co-adsorbent. Different parameters like concentration of ACG dye, irradiation time, catalyst concentration and pH have also been studied. The pseudo first order kinetic equation was found to be applicable in the present dye-catalyst systems. It was observed that photocatalytic degradation by ZnO along with AC was a more effective and faster mode of removing ACG from aqueous solutions than the ZnO alone

Synthesis and corrosion protection properties of poly(o-phenylenediamine) nanofibers

AbstractThe present study shows a novel method for the synthesis of uniformly-shaped poly(othophenylediamine) (PoPD) nanofibers by chemical oxidative polymerization method for application towards smart corrosion resistance coatings. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) studies confirm morphology of PoPD with three dimensional (3D) networked dendritic superstructures having average diameter of 50–70nm and several hundred meters of length. UV–vis and FTIR spectral results shows the formation of PoPD nanofibers containing phenazine ring ladder-structure with benzenoid and quinoid imine units. Thermogravimetric analyses (TGA) of PoPD nanofibers possess good thermal stability. The anti-corrosion behavior of PoPD nanofibers on 316L SS was investigated in 3.5% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) measurements. The PoPD coated 316L SS exhibits higher corrosion potential when compared to uncoated specimen. EIS studies, clearly ascertain that PoPD nanofiber coatings exhibits excellent potential barrier to protect the 316L SS against corrosion in 3.5% NaCl

Synchronous role of coupled adsorption and photocatalytic degradation on CAC–TiO2 composite generating excellent mineralization of alizarin cyanine green dye in aqueous solution

The synchronous role of coupled adsorption and photocatalytic degradation of alizarin cyanine green dye (ACG) in aqueous solution on porous Commercial Activated Carbon (CAC)–titanium dioxide (TiO2) mixture have been studied under UV irradiation. The CAC–TiO2 composite was prepared by simple chemical route and the as prepared composite was characterized using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. The photodegradation rate constant (k) for ACG dye on CAC–TiO2 is (0.0666 min−1), which is very much higher than that of pure TiO2 0.00368 min−1. The photodegradation efficiency of the CAC–TiO2 composite was eighteen order magnitudes higher than that of pure TiO2 for ACG dye degradation. The total mineralization of ACG, through the combination of adsorption and degradation was achieved in a reasonable time, and can therefore be suggested as an efficient, cost-effective and environment friendly water treatment methodology