Mesoporous transition metal oxides (MTMO) with large surface area, nanocrystalline framework, and controlled porosity have brilliant prospects in fields such as energy, environment, catalysis, or nanomedicine. However, the green, reproducible, and scalable production of MTMO are still a bottleneck for their industrial applications. Although spray-drying methods permit to obtain MTMO in a potentially scalable fashion, the use of highly acidic alcoholic precursor solutions presents two main limitations: corrosion and flammability, which hinder their production in large quantities and lower cost. In this work, we present a general, reproducible, simple, and environment-friendly aerosol method for the synthesis of spherical MTMO particles from mildly acidic aqueous solutions. Acetylacetonate and acetate are used as condensation-controlling agents. Mixed oxides of high valence cations (M(IV) such as Ti, Zr, Ce, and their mixed oxides) were prepared with a yield over 95%, virtually without changing the formulation of the precursor mixture, which can be extended potentially to M(III) or M(V) oxides. The replacement of organic solvents by water allows working in air atmosphere, making this approach much safer, cheaper and environmentally friendly than the current aerosol-based routes. We also present the beneficial effect of mesoporous titania spheres as an additive to nickel electrodes used in the hydrogen evolution reaction, as a demonstrator to potential applications. A threefold increase in the electrocatalytic hydrogen production is observed in mesoporous titania-modified nickel electrodes with respect to a pure nickel catalyst. This performance can be further improved ~25% upon UVA-visible irradiation, due to the photoelectrocatalytic effect of the mesoporous TiO₂.

具有大表面积，纳米晶框架和受控孔隙度的中孔过渡金属氧化物（MTMO）在能源，环境，催化或纳米医学等领域具有光明的前景。但是，绿色，可复制和可扩展的MTMO生产仍然是其工业应用的瓶颈。尽管喷雾干燥方法允许以潜在可扩展的方式获得MTMO，但使用高酸性的醇类前体溶液存在两个主要限制：腐蚀和易燃性，这阻碍了它们的大量生产和较低的成本。在这项工作中，我们提出了一种从轻度酸性水溶液中合成球形MTMO颗粒的通用，可再现，简单且环保的气溶胶方法。乙酰丙酮酸酯和乙酸酯用作缩合控制剂。制备高价阳离子的混合氧化物（M（IV），例如Ti，Zr，Ce及其混合氧化物），收率超过95％，几乎无需改变前体混合物的配方即可将其扩展至M （III）或M（V）氧化物。用水代替有机溶剂可以在大气中工作，与目前的气雾剂生产方法相比，这种方法更加安全，便宜和环保。我们还提出了介孔二氧化钛球作为氢析出反应中使用的镍电极添加剂的有益作用，作为潜在应用的证明。相对于纯镍催化剂，在介孔二氧化钛改性的镍电极中观察到电催化产氢量增加了三倍。₂。