The metal ions (Ti⁺⁴, Mg⁺², Zn⁺² and Co⁺²) have been substituted in place of Al$^{+3}$ in aluminophosphates (AlPOs). These compounds were used for the first time as possible photocatalysts for the degradation of organic dyes. Among the doped AlPOs, ZnAlPO-5, CoAlPO-5, MgAlPO-11, 18 and 36 did not show any photocatalytic activity. MgAlPO-5 showed photocatalytic activity and different loading of Mg (4, 8, 12 atom % of Mg) were investigated. The activity can be enhanced by the increasing of concentration of the doped metal ions. TiAlPO-5 (4, 8, 12 atom % of Ti) showed the highest photocatalytic activity among all the compounds and its activity was compared to that of Degussa P25 (TiO₂). The activity of photocatalysts was correlated with the diffuse reflectance and photoluminescence spectra.

Scheelite type solid electrolytes, Li_0.5Ce$_{0.5−x}$Ln$_x$MoO₄ ($x = 0$ and 0.25, Ln = Pr, Sm) have been synthesized using a solid state method. Their structure and ionic conductivity (𝜎) were obtained by single crystal X-ray diffraction and ac-impedance spectroscopy, respectively. X-ray diffraction studies reveal a space group of $I4_1/a$ for Li_0.5Ce$_{0.5−x}$Ln$_x$MoO₄ ($x = 0$ and 0.25, Ln = Pr, Sm) scheelite compounds. The unsubstituted Li_0.5Ce_0.5MoO₄ showed lithium ion conductivity $\sim 10^{−5}-10^{−3} \Omega^{−1}$cm^-1 in the temperature range of 300-700°C ($\sigma = 2.5 \times 10^{−3} \Omega^{−1}$cm^-1 at 700°C). The substituted compounds show lower conductivity compared to the unsubstituted compound, with the magnitude of ionic conductivity being two (in the high temperature regime) to one order (in the low temperature regime) lower than the unsubstituted compound. Since these scheelite type structures show significant conductivity, the series of compounds could serve in high temperature lithium battery operations.

Palladium substituted in cerium dioxide in the form of a solid solution, Ce_0.98 Pd_0.02 O_1.98 is a new heterogeneous catalyst which exhibits high activity and 100% trans-selectivity for the Heck reactions of aryl bromides including heteroaryls with olefins. The catalytic reactions work without any ligand. Nanocrystalline Ce_0.98 Pd_0.02 O_1.98 is prepared by solution combustion method and Pd is in +2 state. The catalyst can be separated, recovered and reused without significant loss in activity.

In the present study, KBiO₃ is synthesized by a standard oxidation technique while LiBiO₃ is prepared by hydrothermal method. The synthesized catalysts are characterized by X-ray diffraction (XRD), Scanning ElectronMicroscopy (SEM), BET surface area analysis and Diffuse Reflectance Spectroscopy (DRS). The XRD patterns suggest that KBiO₃ crystallizes in the cubic structure while LiBiO₃ crystallizes in orthorhombic structure and both of these adopt the tunnel structure. The SEM images reveal micron size polyhedral shaped KBiO₃ particles and rod-like or prismatic shape particles for LiBiO₃. The band gap is calculated from the diffuse reflectance spectrum and is found to be 2.1 eV and 1.8 eV for KBiO₃ and LiBiO₃, respectively. The band gap and the crystal structure data suggest that these materials can be used as photocatalysts. The photocatalytic activity of KBiO₃ and LiBiO₃ are evaluated for the degradation of anionic and cationic dyes, respectively, under UV and solar radiations.

Transition metal oxide (TiO₂, Fe₂O₃, CoO) loaded MCM-41 and MCM-48 were synthesized by a two-step surfactant-based process. Nanoporous, high surface area compounds were obtained after calcination of the compounds. The catalysts were characterized by SEM, XRD, XPS, UV-vis and BET surface area analysis. The catalysts showed high activity for the photocatalytic degradation of both anionic and cationic dyes. The degradation of the dyes was described using Langmuir-Hinshelwood kinetics and the associated rate parameters were determined.

We have demonstrated a simple, scalable and inexpensive method based on microwave plasma for synthesizing 5 to 10 g/h of nanomaterials. Luminescent nano silicon particles were synthesized by homogenous nucleation of silicon vapour produced by the radial injection of silicon tetrachloride vapour and nano titanium nitride was synthesized by using liquid titanium tetrachloride as the precursor. The synthesized nano silicon and titanium nitride powders were characterized by XRD, XPS, TEM, SEM and BET. The characterization techniques indicated that the synthesized powders were indeed crystalline nanomaterials.