The photocatalytic reduction of dinitrogen to ammonia is influenced by the nature and amount of metal loading on TiO2. The optimum metal content varies depending on the nature of the metal. A correlation between the ammonia yield and the intermediary M-H bond strength is established (low bond strength gives rise to low ammonia yield).

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

Photocatalytic reduction of dinitrogen to ammonia over noble-metal-loaded TiO2

Journal of Photochemistry and Photobiology A: Chemistry

Two wet chemical methods, namely, wet etching (heterogeneous) and chemical precipitation (homogeneous), have been exploited for the formation of hierarchical ZnO architectures without any specific templates, catalysts, or capping agents. As-synthesized ZnO have been extensively characterized by X-ray diffraction, UV-visible absorbance studies, Fourier transform infrared analysis, scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive analysis of X-rays, selected area electron diffraction, photoluminescence (PL), and textural analysis. Wet etching resulted in the formation of self-assembled hexagonal plates with a disordered superlattice-type texture and ultimately ended up in crystallites with high-defect concentration showing a red PL emission. Mechanistic aspects of the growth process in both the methods have been analyzed, and a rational explanation is presented for their observed morphologies. ZnO prepared by both methods have been tested for their photocatalytic water splitting abilities in producing H2. Crystalline, spectral, textural, and activity analyses have been carried out for commercial ZnO for a comparison. Pt loaded ZnO was used for the concurrent hydrogen generation and dinitrogen fixation yielding a maximum of 86 μmol of ammonia/(h/0.1 g of catalyst), thus achieving the activation of N2 at room temperature and atmospheric pressure. © 2010 American Chemical Society.

Journal of Physical Chemistry C

Heterogeneous wet chemical synthesis of superlattice-type hierarchical ZnO architectures for concurrent H2 production and N2 reduction

Mesoporous CdS nanoparticles with an average pore size of 54 Å and a particle size of 4-6 nm have been prepared by template free ultrasonic mediated precipitation at room temperature. The as prepared particles have been characterized by UV-vis spectroscopy, XRD, N2 adsorption-desorption isotherms, SEM and TEM techniques. The photocatalytic hydrogen production activity for the pure, noble metal loaded and supported mesoporous CdS has been studied. The photocatalytic activity has been compared with bulk and nanosize CdS prepared in our earlier studies. Among the prepared catalysts, Pt metal loaded mesoporous CdS shows highest hydrogen production rate of 1415 μmol/h/0.1 g catalyst. In the case of supported systems, irrespective of the particle size the basic MgO support shows higher activity than alumina support. © 2007 Elsevier B.V. All rights reserved.

Catalysis Today

Photocatalytic generation of hydrogen over mesoporous CdS nanoparticle: Effect of particle size, noble metal and support

Cadmium sulphide nanoparticles (6-12 nm) are prepared by a precipitation process using different zeolite matrices as templates. The nanoparticles were characterized by UV-Vis, XRD, SEM, TEM and sorptometric techniques. XRD study shows the presence of hexagonal and cubic phases for the nanoparticles whereas in case of the bulk samples only the hexagonal phase is observed. These nanomaterials have been used as catalysts for the photocatalytic decomposition of water. The nanoparticles show a higher hydrogen evolution rate compared to the bulk samples which correlates well with the particle size and surface area. Noble metal (Pt, Pd, Rh, Ru)-loaded samples were subsequently prepared and tested for hydrogen evolution reaction. The presence of Pt metal is found to enhance the hydrogen production rate whereas the hydrogen production rate is retarded in the presence of Ru metal. This has been explained on the basis of metal hydrogen bond, redox potential and work function of the noble metal. © 2005 International Association for Hydrogen Energy.

International Journal of Hydrogen Energy

Alternate synthetic strategy for the preparation of CdS nanoparticles and its exploitation for water splitting

Applied Catalysis B: Environmental

Photocatalytic reduction of nitrogen over (Fe, Ru or Os) /TiO2 catalysts

Journal of Molecular Catalysis

Photosensitized reduction of N2 by RuII(bipy)32+ adsorbed on the surface of Pt/TiO2/RuO2 semiconductor particulate system containing RuIII-EDTA complex and L-ascorbic acid

Solar Energy Materials

Photoinduced oxidative nitrogen fixation reactions on semiconductor suspensions

J. Chem. Soc., Chem. Commun.

Fixation of molecular nitrogen on a rhodium/titanium dioxide SMSI (strong metal–support interaction) catalyst

ChemInform

ChemInform Abstract: Heterogeneous Photoreduction of Nitrogen to Ammonia on Tungsten Oxide.

Journal	Data powered by TypesetJournal of Photochemistry and Photobiology A: Chemistry
Publisher	Data powered by TypesetElsevier
ISSN	10106030
Open Access	No