CAREER: Advanced Aerosol Synthesis of Metal Oxides for Photocatalytic Applications

技术概述最重要的是发现新的合成技术，这些技术可以被可预测地操作以产生具有确定和可控特征的材料。虽然被广泛认为是合成复杂无机固体的有力途径，但超声喷雾热解（USP）（其是使用超声进行雾化的基于气溶胶的合成技术）作为合成结构多样性颗粒的合成途径尚未得到充分认识。这个由固态和材料化学（SSMC）计划支持的CAREER项目将强调前体设计和分解行为，以及气溶胶液滴相和表面化学，以实现具有USP的结构多样性颗粒，用于光催化应用，包括用于太阳能H2产生的水分解。 合成目标包括i）高度定制的二氧化钛光催化剂，其中孔隙率、晶相分布和表面装饰受到控制，和ii）具有高活性位点分散的可见光驱动的O2释放光催化剂。前者将通过利用新发现的盐辅助途径来实现多孔颗粒，其中低熔点盐混合物作为孔模板，预形成的二氧化钛胶体作为较大多孔颗粒的构建块。 后者将通过靶向价带改性的过渡金属氧化物来实现。 在这种情况下，结构多样的颗粒将通过USP通过偏离惯例并选择经由i）反应（例如，复分解方法）或ii）从单源前体分解。 鉴于拟议的研究解决了这样一个及时的问题，可持续能源的发展，这也是非常重要的，花了相当大的努力，教育社会关于这一点。为此，能源大使计划的建议，其中大学生，在高级实验室成员的指导下，回到他们的高中，通过一个引人入胜的演示来讨论他们的研究。大量资源正被用于开发替代能源平台，以试图将与化石燃料燃烧相关的潜在灾难性影响降至最低。燃料. 鉴于太阳为地球提供了120，000万亿瓦（TW）的能量，太阳能转换是可持续生产13 TW的最可行的手段，这与全球人类需求一致。 这项研究旨在开发新材料，利用太阳能将水分解为氢（H2）和氧（O2），H2是一种清洁燃料，在使用时不会排放温室气体或其他污染物。 新材料将通过基于气溶胶的合成方法制备，重点是发现新的方法，通过使用化学方法生产结构导向剂来控制所得颗粒的结构和形状。 控制所制备的颗粒的形状和结构潜在地提供了一种方式，其中可以选择性地增强材料的期望特征，从而最大化它们的光捕获特性和表面反应性。鉴于拟议的研究解决了这样一个及时的问题，同样重要的是，努力教育社区关于太阳能科学。 因此，提出了一个能源大使计划，其中本科生，从高级实验室成员的指导下，返回他们的高中，通过一个引人入胜的演示讨论他们的研究。

TECHNICAL SUMMARYOf fundamental importance is the discovery of new synthetic techniques that can be predictably manipulated to yield materials with defined and controllable features. While widely recognized as a powerful route to compositionally-complex inorganic solids, ultrasonic spray pyrolysis (USP), which is an aerosol-based synthetic technique that uses ultrasound for nebulization, has been under-realized as a synthetic route to architecturally-diverse particles. This CAREER project, supported by the Solid State and Materials Chemistry (SSMC) program will emphasize precursor design and decomposition behavior, as well as aerosol droplet phase and surface chemistry, to achieve architecturally-diverse particles with USP for photocatalytic applications including water splitting for solar H2 generation. Synthetic targets include i) highly-tailored titania photocatalysts in which porosity, crystal phase distribution, and surface decoration are controlled and ii) visible light driven O2-evolving photocatalysts with high active site dispersion. The former will be achieved by exploiting a newly discovered salt-assisted route to porous particles in which low-melting salt mixtures serve as a pore template and pre-formed titania colloids serve as the building blocks to the larger porous particles. The latter will be achieved by targeting valence band modified transition metal oxides. In this case, architecturally-diverse particles will be achieved with USP by deviating from convention and selecting precursors that yield templates and/or structure-directing agents via i) reaction (e.g., metathesis approaches) or ii) decomposition from single-source precursors. Given that the proposed research addresses such a timely issue, the development of sustainable energy sources, it is also of utmost importance that considerable effort be spent educating the community about it. To this aim, an Energy Ambassadors' Program is proposed in which undergraduates, with guidance from senior laboratory members, return to their high schools to discuss their research through an engaging demonstration.NON-TECHNICAL SUMMARYSubstantial resources are being directed toward the development of alternative energy platforms in attempts to minimize the potentially catastrophic effects associated with the burning of fossil fuels. Given that the sun provides the Earth with 120,000 trillion watts (TW) of energy, solar energy conversion represents the most viable means of sustainably producing 13 TW, which is consistent with global human demand. The proposed research aims to develop new materials for harnessing the energy of the sun to split water into hydrogen (H2) and oxygen (O2), with H2 representing a clean fuel that does not emit greenhouse gases or other pollutants upon use. The new materials will be prepared by an aerosol-based synthetic approach, with an emphasis on discovering new ways in which the architecture and shape of the resulting particles can be controlled by producing structure-directing agents using chemical methods. Controlling the shape and architecture of the prepared particles potentially provides a way in which the desirable features of a material can be enhanced selectively, thus maximizing their light harvesting properties and surface reactivity. Given that the proposed research addresses such a timely issue, it is also important that effort be spent educating the community about solar energy science. Thus, an Energy Ambassadors' Program is proposed in which undergraduates, with guidance from senior laboratory members, return to their high schools to discuss their research through an engaging demonstration.