Bio-inspired photonics and surface engineering for sustainable energy materials

化石燃料的快速消耗及其带来的生态和环境问题，需要探索以可再生绿色资源为中心的解决方案。在绿色能源生产的各种替代方法中，光电催化(PEC)是一种非常有前途的同时解决能源和环境问题的方法。PEC提供了以高密度燃料的形式储存断断续续但丰富的太阳能的潜力，尤其是氢(H2)。实现高效制氢的主要里程碑之一是优化光吸收材料，包括增强对太阳辐射的吸收并产生足够数量的电子(e-)和空穴(h+)来驱动热力学上坡的氧化还原过程，以及与其他相相互作用的材料表面形态和化学结构。-该项目试图解决的研究问题/该项目的目标：1.该项目旨在开发光催化材料的新制备方法。我们要研究的问题如下：在多相光催化过程中，通常使用廉价和丰富的、在UV-Vis范围内带隙的金属氧化物(MOS)作为催化剂。1)为了实现高效的光催化分解水，需要开展MOS的带隙工程研究，以适应整个分解水过程的能量需求。2)此外，许多宽禁带MO半导体在可见光谱范围内对制氢的催化活性有限，从而阻碍了对太阳辐射的充分利用。3)此外，良好的化学稳定性和光激发电子(e-)和反应空穴(h+)之间有效的电荷分离对于光催化剂和电化学反应都是至关重要的。在本项目的目标方面，我们将重点放在利用材料的光子特性上，目的是提高MOS的光催化性能。这将通过改善光催化材料的纳米工程化结构，促进MO带隙的变化，提供高比表面积，并增强(e-)-(h+)对的迁移率来实现。具体地说，我们的方法包括合成可持续的光子纳米结构，特别是具有可控的长程和短程晶序的晶体结构，作为MOS的模板材料。2)以光子晶体形式实现的MO结构有望在可见光范围内提高MOS的光催化性能。这种增强可以通过在光子带隙边缘通过阻带实现显著增强的光-材料相互作用，阻带是一个禁止传播的频率范围。3)晶体结构和这些结构中光子和电子带隙的重叠延长了(e-)-(h+)对的寿命，从而促进了更有效的电荷分离。4)表面纹理的调整是为了在捕光能力、晶体结构和气泡形成和释放过程中的潜在损失之间取得平衡。

The rapid consumption of fossil fuels and its consequential ecological and environmental issues necessitate the exploration of solutions centered around renewable green resources. Among the various alternative methods of green energy production, photoelectrocatalysis (PEC) emerges as a highly promising approach for simultaneously addressing energy and environmental concerns. PEC offers the potential to store intermittent yet abundant solar energy in the form of high-density fuels, notably hydrogen (H2). One of the major milestones in achieving efficient hydrogen production lies in the optimization of the photo absorbers, involving processes that enhance the absorption of solar radiation and generate a sufficient number of electrons (e-) and holes (h+) to drive the thermodynamically uphill redox processes, as well as material surface morphology and chemical structure that interact with other phases. - the research questions the project is trying to address/the objectives of the project:1. This project aims to develop novel fabrication methods for photocatalytic materials. The research questions we aim to address are as follows: In heterogeneous photocatalytic processes, inexpensive and abundant metal oxides (MOs) with bandgaps in the UV-Vis range are commonly employed as catalysts. 1) To achieve efficient photocatalytic water splitting, research on band gap engineering of MOs needs to be developed to align with the energy requirements of the overall water splitting process. 2) Also, many wide-bandgap MO semiconductors encounter limited catalytic activity for hydrogen production within the visible spectral range, thereby impeding the sufficient utilization of solar radiation. 3) Moreover, good chemical stability and efficient charge separation between photoexcited electrons (e-) and reactive holes (h+) are critical for both photocatalysts and electrochemical reactions.2. In terms of objectives in this project, we focus on harnessing the photonic characteristics of materials, with the objective of enhancing the photocatalytic performance of MOs. This will be accomplished by improving the nanoengineered structure of photocatalytic materials, facilitating changes in MO bandgap, providing high surface area, and enhancing the mobility of (e-) - (h+) pairs.Specifically, 1) Our approach involves the synthesis of sustainable photonic nanostructures, specifically crystalline structures with controlled long-range and short-range crystalline orders, which serve as template materials for MOs. 2) The implementation of MO structures in the form of photonic crystals is anticipated to enhance the photocatalytic performance of MOs within the visible light range. This enhancement can be achieved through significantly augmented light-material interaction at the edge of the photonic bandgap via the stop band, a frequency range that forbids propagation. 3) The crystal structure and overlap of the photonic and electronic band gaps in these structures extend the lifetimes of (e-) - (h+) pairs, thereby facilitating more efficient charge separation. 4) Tuning of the surface texture is undertaken to strike a balance between light-harvesting capacity, crystal structure, and potential losses during bubble formation and release.