2023-07-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/672190以太陽光能從水光催化製氫是一種有吸引力的策略，在現階段，它還不能提供最高的太陽能製氫效率(solar-to-hydrogen, STH) ，但是這個過程是最便宜、最簡單且適合擴大規模。所有這些原因都加強了開發新型和更高效的製氫光觸媒的研究。通過光催化過程實現高 STH 效率的主要瓶頸通常與快速電荷複合、低效的光收集和驅動複雜的多電子氧化還原過程的無效催化位點有關。在 HetCat 項目中，我們創新地採用形態學、電子和結構設計原則來設計優化的新型光催化系統，從而應對這些挑戰。 歐盟合作計畫提出基於金屬鈦酸鹽和鈮酸鹽的薄膜二維 (2D) 奈米結構及其在 2D/2D (晶膜)異質結構中的創新集成，其中復合率由於厚度小 (實現短電荷傳輸路徑)和/或通過內部電場，形成於 2D/2D 大接觸面積界面。此外，通過還原捕獲的 Bi3+ 離子形成的金屬 Bi 的表面等離子共振 (surface plasmon resonance, SPR) 效應，可以將 Bi 前驅物以水熱拓撲化學轉化衍生的新型二維結構和異質結構作為具有增強光催化效率的光催化劑。為了更好地利用太陽光譜的可見光部分，另一種提出的創新光觸媒是 2D/2D 奈米異質結構，它結合了提出的 2D 複合金屬氧化物和窄能隙帶 g-C3N4 奈米片。 2D/2D 異質結構對應物的選擇將基於材料結構相容性(晶膜異質結構)，並考慮它們的能帶結構以結合材料，從而形成有利的電荷轉移 (例如直接 Z-scheme)。這個材料工程步驟將以密度泛函理論 (density functional theory, DFT)模擬計算支持電子結構預測和界面模型。光觸媒的製備將基於我們已有的經驗和對水熱法晶膜生長和拓撲化學轉化原理的深入理解，通過實驗來實現。借助多尺度計算模擬、先進的界面原子尺度分析、現代電荷載流子動力學探測方法和光催化測試，我們將能夠深入了解光催化過程，確定界面電荷轉移機制並選擇最佳材料組合。所有這些連同創新的光觸媒設計、優化的光反應器系統，將可實現前所未有的高光催化效率的潛力。我們有抱負的目標是開發 STH 接近 2% 的光觸媒。本計畫將從 TRL 2 開始，到 TRL4 結束。根據綠色政綱目標的理念，光催化製氫在選擇材料和合成程序時還會考慮可持續性和可回收性方面。 Photocatalytic solar hydrogen production from water is one of the appealing strategies, which at the current stage, does not provide the highest solar-to-hydrogen (STH) efficiency, nevertheless this process is the cheapest, simplest and appropriate for scale-up. All these have intensified the research for development of new and more efficient hydrogen-evolution photocatalysts. The main bottlenecks in achieving high STH efficiency through photocatalytic process are most commonly associated with rapid charge recombination, inefficient light harvesting and ineffective catalytic sites for driving complex multi-electron redox processes. In the HetCat project, we aimed to address these challenges by innovative employing morphological, electronic and structural design-principles for engineering of optimized new photocatalytic system. We propose metal titanate and niobate-based thin two-dimensional (2D) nanostructures and their innovative integration in 2D/2D (epitaxial) heterostructures, in which recombination rate is diminished due to small thickness (enabling short charge transport path) and/or by internal electric field, formed at the 2D/2D large contact area interface. Furthermore, novel 2D structures and heterostructures derived through hydrothermal topochemical conversion of Bi-based precursors are suggested as photocatalysts with enhanced photocatalytic efficiency due to surface plasmon resonance (SPR) effect of metallic Bi, formed by reduction of captured Bi3+ ions. Another proposed innovative photocatalysts for better utilization of the visible part of the solar spectrum are 2D/2D nanoheterostructures combining proposed 2D complex metal oxides with narrow-band-gap g-C3N4 nanosheets. The selection of 2D/2D-heterostructure counterparts will be based on materials structural compatibilities (epitaxial heterostructures) and on the consideration of their band-structures to combine materials, that enable formation of favorable charge transfer (e.g. direct Z-scheme). This material engineering step will be supported by density functional theory (DFT) calculations for predictions of electronic structures and modelling the interfaces. Preparation of the photocatalysts will be experimentally realized based on our pre-existing experiences and in-depth understanding of the principles of hydrothermal epitaxial growth and topochemical transformation. With the help of multiscale computer modelling, advanced atomic scale analysis of the interface, modern methods for probing the charge carrier dynamics and photocatalytic testing, we will be able to get insight into the photocatalytic process, identify interfacial charge transfer mechanism and select the best materials combinations. All these, together with innovative photocatalysts design, optimized photoreactor system represent the potential to result in unprecedented high photocatalytic efficiencies. Our ambitious goal is to develop photocatalysts with STH close to 2 %. The proposed project will start at TRL 2 and end at TRL4. In line with the project idea (photocatalytic hydrogen production), that supports Green Deal goals, the aspects of sustainability and recyclability will be also considered in the selection of materials and synthesis procedures.光催化;鈣鈦礦;太陽氫能;密度泛函理論;光反應器;photocatalysis; perovskite; solar hydrogen; DFT; photoreactor