The present study focuses on the development of high surface area nanostructures and their applications in the removal of gas-phase contaminants through both photocatalytic and adsorptive techniques. Particular importance was given to ensure the commercial viability of the developed technologies. Due to its industrial importance, the elimination of siloxanes from biogas was investigated with major interest. Through electrospinning techniques it was possible to synthesise a large number of nanostructures: TiO2, SiO2, WO3, and WO3 doped TiO2 nanofibres. These structures were further enhanced through templating techniques in order to make core/shell SiO2/TiO2 nanofibres, hollow TiO2 nanofibres, and porous TiO2 nanofibres. Additionally, the synthesis of SiO2 aerogel granules under ambient conditions was performed through a novel, commercially facile, technique. The created nanostructures were initially employed as adsorptive materials for the removal of gaseous siloxanes from static environments. The adsorption kinetics and total siloxane loadings of the created structures were compared to those of P25, commercial silica gel, and the industrial PpTek siloxane removal standard. Although the commercial adsorbents were shown to perform better than the created nanostructures, the nanostructure surface areas were seen to lead to enhanced adsorptive properties with respect to P25. TiO2 nanofibres, porous TiO2 nanofibres, WO3 doped TiO2 nanofibres, and P25 were further used to study the photodecomposition of siloxanes in a static environment. Through kinetic studies it was possible to establish that 1 mol% WO3 doped TiO2 nanofibres were an ideal candidate for the photodecomposition of gaseous siloxanes, with a decomposition rate 126.5 % larger than that of simple P25. P25 was coated on glass beads through a novel technique in order to photocatalytically degrade contaminants in gas flows. Through the decomposition of both siloxanes and VOCs it was possible to study the turnover numbers and conversion levels of the reactions. The poisoning of the catalysts was identified and countered through industrially viable recoating techniques. From these studies it was possible to develop a prototype reactor for the photodecomposition of siloxanes in biogas. Finally, the synthetic properties of the flow reactors were studied by carrying out the photoepoxidation of hexene over P25. These studies were further enhanced by reacting the partial photoepoxidation products of the reactor's exhaust in order to create rare and complex organic species.