Polycrystalline mercury sulphide (HgS) thin film at room temperature and in acidic condition was deposited on amorphous glass substrate by using improved chemical bath deposition technique. The structural and morphological analysis of as-deposited and annealed films was carried out by X-ray diffraction and scanning electronic microscopic technique. Ultraviolet and d.c. electrical resistivity measurement were made to study electrical and optical properties of the thin films. The outcome indicates formation of well-crystallized pure $\beta$HgS thin films having good electrical and optical properties. For this reason, HgS thin film in acidic medium was deposited properly by using chemical bathdeposition technique.

Nanocrystalline nickel ferrite (NiFe2O4) was synthesized by economical sol–gel auto-combustion method. XRD pattern confirms existence of cubic spinel phase with average crystallite size of 28.37 nm. The magnetic andmorphological properties of the sample were studied by using vibratory sample magnetometer (VSM) and scanning electron microscope (SEM), respectively. The prepared samples were used to study photocatalytic degradation of rhodamine B dye solution. The effect of UV light irradiation time, metal doping and kinetic parameters of photocatalysis with nickel ferrite catalyst was studied in detail. The catalyst was also utilized for a two-element coupling system of phenylhalide and phenyl boronic acid. The influence of solvent, temperature and metal loading of the catalyst was conjointly mentioned.