CAS: 2D-WS2 Supported 2D-ZnO Nanoislands for Visible-Light-Driven Photocatalysis

CAS：2D-WS2 支持的 2D-ZnO 纳米岛用于可见光驱动光催化

• 批准号: 2247800
• 负责人: Arjun Dahal
• 金额: $ 30.09万
• 依托单位: University of South Alabama
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-15 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247800&HistoricalAwards=false
• 关键词: CAS; 2D; WS2; Supported; ZnO

With support from the Chemical Catalysis (CAT) program in the Division of Chemistry, and the Established Program to Stimulate Competitive Research (EPSCoR), Dr. Arjun Dahal of the University of South Alabama is studying designing of innovative heterostructure photocatalysts, which have the potential to become disruptive photocatalysts for environmentally benign and sustainable energy production. Scientific breakthroughs in developing innovative and green energy technologies can move economies away from fossil fuels, reducing the effects of climate change. Hydrogen possesses the highest energy content per weight among combustion fuels and produces only water as the product; therefore, hydrogen is regarded as a promising "green fuel." Hydrogen production from the photocatalysis process by splitting water utilizing sunlight and photocatalyst materials is a promising method of generating clean energy. Designing innovative photocatalysts is the primary step to realize efficient hydrogen production. Dr. Dahal is developing innovative, low-cost, and potentially highly efficient heterostructure photocatalysts comprising two-dimensional (2D) metal oxides and 2D transitional metal dichalcogenides. As part of the project, Dr. Dahal will also examine the correlation between the photocatalytic efficiency of the heterostructures to their size, density, chemical composition, and electronic properties. The project will offer opportunities to train students in cutting-edge nanoscale science within the context of modern energy and environmental applications. The proposed research is strongly interdisciplinary and teaches students physics and chemistry concepts that better prepare students for entry into advanced degree programs and/or careers in academia and industry. In this project, the Dahal research group is studying fabrication methods and growth mechanisms of heterostructures incorporating 2D-ZnO and 2D-WS2. Dr. Dahal will implement the physical vapor deposition (PVD) approach to grow 2D-ZnO nanoislands on the 2D-WS2 support prepared using the chemical vapor deposition (CVD) method. PVD is a desirable method because it enables the control over morphology, size, density, chemical composition, and electronic properties of the heterostructures. Dr. Dahal will characterize nanostructure morphology, size, and density using atomic force microscopy. Photoemission will give insight into the chemical composition and electronic states of these heterostructures, and the conducting mapping measurements should provide additional insight into the quality of the interfaces. The PVD and CVD growth methods have the potential to enable the formation of high-quality interfaces. Dahal and his team will evaluate the photocatalytic efficiency by measuring the rate of degradation of an organic dye solution in the presence of these heterostructures under UV/visible irradiation. The group will also directly quantify hydrogen evolution efficiency from water-splitting reactions under light irradiation using the gas chromatography technique. Due to the synergistic effects, the proposed heterostructures can potentially be more efficient than conventional photocatalysts because they can offer a wider light-harvesting range, enable a low probability of charge recombination, and provide many active reaction sites on exposed surfaces. In terms of broader scientific impact, this project has the potential to bring forward a new class of photocatalysts using 2D metal oxides and 2D transition metal dichalcogenides and is expected to provide useful information on the properties of the target heterostructures such as crystallinity, crystallinity phases, surface structures, band gap modifications, and defects.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在化学部化学催化（CAT）计划和刺激竞争研究（EPSCoR）的既定计划的支持下，南亚拉巴马大学的Arjun Dahal博士正在研究创新异质结构光催化剂的设计，这些光催化剂有可能成为环境友好和可持续能源生产的破坏性光催化剂。在开发创新和绿色能源技术方面的科学突破可以使经济摆脱化石燃料，减少气候变化的影响。氢是燃烧燃料中单位重量能量含量最高的燃料，其燃烧产物仅为水，因此被认为是一种很有前途的“绿色燃料”。“利用太阳光和光催化剂材料分解水，从水分解过程中制氢是一种很有前途的清洁能源生产方法。设计创新的光催化剂是实现高效制氢的首要步骤。Dahal博士正在开发创新的，低成本的，潜在的高效异质结构光催化剂，包括二维（2D）金属氧化物和2D过渡金属二硫属化物。作为该项目的一部分，Dahal博士还将研究异质结构的光催化效率与其尺寸，密度，化学成分和电子特性之间的相关性。该项目将提供机会，在现代能源和环境应用的背景下，培养学生在尖端纳米科学。拟议的研究是强烈的跨学科和教学生物理和化学概念，更好地准备学生进入高级学位课程和/或职业生涯在学术界和工业界。在这个项目中，Dahal研究小组正在研究将2D-ZnO和2D-WS 2结合在一起的异质结构的制造方法和生长机制。Dahal博士将实施物理气相沉积（PVD）方法，在使用化学气相沉积（CVD）方法制备的2D-WS 2载体上生长2D-ZnO纳米岛。 PVD是一种理想的方法，因为它能够控制异质结构的形态、尺寸、密度、化学组成和电子性质。Dahal博士将使用原子力显微镜表征纳米结构的形态、大小和密度。光电发射将深入了解这些异质结构的化学成分和电子状态，并且传导映射测量应该提供对界面质量的额外了解。PVD和CVD生长方法具有形成高质量界面的潜力。Dahal和他的团队将通过测量在紫外/可见光照射下这些异质结构存在下有机染料溶液的降解速率来评估光催化效率。该小组还将使用气相色谱技术直接量化光照射下水裂解反应的析氢效率。由于协同效应，所提出的异质结构可能比传统的光催化剂更有效，因为它们可以提供更宽的光捕获范围，使电荷复合的可能性低，并在暴露的表面上提供许多活性反应位点。在更广泛的科学影响方面，该项目有可能提出一种使用2D金属氧化物和2D过渡金属二硫属化物的新型光催化剂，并有望提供有关目标异质结构性质的有用信息，如结晶度，结晶相，表面结构，带隙改性，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。