Novel Materials based on Nanocrystalline Oxide Doping of Glasses

受污染的水代表着严重的经济和人类成本。在印度这样的中等收入国家，水污染是一个大问题，其经济影响相当于下游地区GDP增长的近一半损失[1]。事实上，据估计，每天有近4000万升废水进入印度的河流和其他水体，其中只有一小部分得到了适当的处理。这种上游污染的释放与农业收入和产量的显著下降有关。为了减少污染物，可以使用物理(过滤、吸附)、化学和生物处理。众所周知，在去除水中的石油和其他污染物方面，基于膜过滤的物理处理比化学和生物处理更可靠。各种吸附剂的吸附被认为是最有效、最经济、最环保的方法，因为吸附后污染物可以被适当地丢弃，而且吸附剂可以多次回收或重复使用。气凝胶是一种海绵状材料，其总体积的98%是空气(因此而得名)，具有优异的物理化学性质，如低密度、高孔隙率、高比表面积和可调节的表面化学，可用于多种应用。特别是，气凝胶作为去除几种威胁环境和人类健康的污染物的吸附介质引起了极大的关注[2]。气凝胶在环境修复中的应用可用于从大气中吸附二氧化碳，用于去除工业和城市污水中的挥发性有机污染物，以及用于吸附石油、危险有机化合物和重金属离子的水处理过程。事实上，上述污染物是当今世界的主要污染源，导致全球变暖和危害人类健康等严重的环境问题。二氧化钛是一种具有优异性能的氧化物材料，被广泛开发用于催化剂、太阳能电池的光阳极组件，甚至作为骨植入的支架。特别是，二氧化钛作为光催化剂的优异性能，意味着照射在二氧化钛上的光将促进化学反应，已被应用于可见光下污染物的降解[3]。在常见的二氧化钛晶型中，锐钛矿因其优越的表面化学性能、更开放的结构和更好的电子扩散而被认为是更活跃的相，这导致了传输效率的提高和更高的带隙。光催化活性确实强烈地依赖于诸如表面积、带隙和物相组成等参数

Polluted water represents a serious economic and human cost. In middle-income countries like India where water pollution is a big problem, the economic impact amounts to a loss of almost half of GDP growth in downstream regions [1]. In fact, it is estimated that every day, almost 40 million litres of wastewater enter rivers and other water bodies in India with only a tiny fraction adequately treated. Such a release of pollution upstream is associated with a significant reduction in agricultural revenues and yields.In order to reduce contaminants, physical (filtration, adsorption), chemical and biological treatments can be used. Physical treatments based on membrane filtration are known to be more reliable than chemical and biological treatments when it comes to removing oil and other contaminants from water. Adsorption by various sorbents is considered to be the most efficient, economical and ecologically benign approach, since the pollutant can be discarded properly after adsorption, and the adsorbant can frequently be recycled or reused several times. Aerogels, which are sponge-like materials, with up to 98% of their total volume being air (hence the name) have excellent physicochemical properties such as low density, high porosity, high surface area and adjustable surface chemistry that can be exploited in several applications. In particular, aerogels have attracted significant attention as an adsorption media for removal of several environmental and human health-threatening pollutants [2]. The use of aerogels in environmental remediation can be applied to CO2 adsorption from atmospheric air, to removal of volatile organic contaminants in industrial and municipal effluents, and to water treatment processes for adsorption of oil, hazardous organic compounds and heavy metal ions. Indeed, the above-mentioned contaminants are the major source of pollution in the contemporary world contributing to serious environmental problems such as global warming and hazards for human health.Titania, TiO2, is an oxide material with excellent properties which are exploited in a wide range of applications, finding use as a catalyst, as a component in photoanodes in solar cells and even as a scaffold in bone implants. In particular, the excellent properties of titania as a photocatalyst, meaning that light falling on titania will enhance chemical reactions, have been applied to the degradation of pollutants under visible light [3]. Among the common crystalline forms of titania, anatase is considered as the more active phase because of its superior surface chemistry, more open framework, and better electron diffusion, which leads to an enhancement in transport efficiency and a higher band-gap. Photocatalytic activity is indeed strongly dependent on parameters such as surface area, band gap, and phase composition