Metals which have high over potential can stabilized Hads species. Thus, Ru loaded TiO2 catalysts can be advantageously used for hydrogenation/reduction reactions. This idea has been extended for the photocatalytic reaction of nitrite and nitrate ions to ammonia and a scheme is suggested for the reduction process. © 1995.

Thirukkallam Kanthadai Varadarajan

Balasubramanian Viswanathan

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Photochemistry and Photobiology, A: Chemistry

The photoelectrochemical reduction of nitrite ions to ammonia on CdS photocatalysts was investigated in the slurry mode. The oxidation and the reduction reactions take place separately, thus, decreasing the electron-hole recombination and enhancing the yield of ammonia. © 2003 Elsevier Science B.V. All rights reserved.

Journal of Photochemistry and Photobiology A: Chemistry

Photoelectrochemical reduction of nitrite ions to ammonia on CdS photocatalysts

Fe-doped TiO2 catalysts were prepared by coprecipitation and the sol-gel method. The anatase to rutile phase transformation is dependent on the nature of the precursor used. Sol-gel-derived iron-doped catalysts show the presence of rutile and pseudobrookite phases, whereas coprecipitated catalysts show only the anatase phase. The role of the dopant ion is primarily to improve the charge separation of the photoproduced electron-hole pairs via a permanent electric field. The photocatalytic activity of the iron-doped catalysts can be explained in terms of the heterojunction formed between the Fe/TiO2 and α-Fe2O3 phases for the sol-gel-derived catalyst. ©1997 Elsevier Science S.A.

Synthesis, characterization and photocatalytic properties of iron-doped TiO2 catalysts

Doping of TiO2 with altervalent cations, Fe3+, Cr3+, Co2+ and Mg2+ leads to a red shift in the onset of absorption. The role of the dopant ions is primarily to improve the charge separation by means of a permanent electric field. Doping of TiO2 also influences the adsorption of reagent species and the resulting photoactivity is a consequence of these two factors. An optimum level of dopant ions is beneficial for the photocatalytic activity of TiO2. © 1997 Elsevier Science S.A.

Photocatalytic reduction of nitrite and nitrate ions over doped TiO2 catalysts

Noble metal loaded TiO2 catalysts have been employed as catalysts for the photocatalytic reduction of nitrite and nitrate ions to ammonia. The yield of ammonia was found to depend on the nature, amount of metal and the method of metallization. An optimum metal content is beneficial for the activity. Beyond the optimum content the activity decreases. © 1997 Elsevier Science S.A.

Photocatalytic reduction of nitrite and nitrate ions to ammonia on M/TiO2 catalysts

CdS catalysts, prepared using difference precursors, were characterized and tested for the photocatalytic reduction of nitrite to ammonia using sodium sulphate and sodium sulphite as sacrificial agents. The catalyst prepared from cadmium nitrate and sodium sulphide and treated at 623 K showed maximum activity. The activity was enhanced by loading with noble metals, such as Ru, Pd or Ir, or by the use of hole transferring agents, such as RuO2. The photoefficiency for the photocatalytic reduction of nitrite to ammonia was found to be 2.6%. © 1995.

Photocatalytic reduction of nitrite on CdS

The photocatalytic reduction of nitrite and nitrate to ammonia was tested on ZnS. The yield of ammonia was found to depend on the precursor used for the preparation of ZnS, the temperature of pre-treatment, the sacrificial agent, the pH, the time of irradiation and the nature of metal loaded on ZnS. © 1994.

Journal	Journal of Photochemistry and Photobiology, A: Chemistry
ISSN	10106030
Open Access	No