人类的不断进步也随之使全球面临严峻的能源与环境危机，亟需开发可再生能源以实现社会长久发展。半导体光催化反应能直接将太阳能转化为清洁的化学能源，被认为是一种解决环境污染与能源危机的有效途径。本论文针对快速高效合成并提升半导体光催化效率的关键问题，结合钙钛矿量子点及相关半导体材料独特的光催化性能，开展快速合成方法和光催化反应应用研究。论文中，通过电喷雾快速高效一步法，快速合成高效稳定的有机-无机杂化钙钛矿量子点异质结光催化剂，具有稳定性好、水中均匀分散的优点；进而，在对其进行全面表征分析的基础上，分别利用氧空位和高价态过渡金属元素调控活性位点电子结构，在水相中实现钙钛矿量子点的高效光催化固氮反应；此外，为了进一步精准调控材料微观结构，还利用变价S元素间接调控邻近Ti原子局域电子结构，增强了半导体材料光催化析氧过程。该系列工作对理解材料的结构与光催化性能的关系有一定的指导意义，拓展了半导体光催化在绿色能源合成领域的应用。本论文包含的主要内容如下：

1. 首先，我们采用电喷雾（ESI）微滴法一步快速合成聚碳酸酯（PC）和一氧化铅（PbO）复合共包覆的Zn掺杂有机-无机杂化钙钛矿（MAPbX₃，X:Br）量子点异质结（Zn/PbO/PC-Zn/MAPbBr₃）材料。Zn/PbO与Zn/MAPbBr₃构成的Type I异质结，有效促进了Zn/PbO和Zn/MAPbBr₃间载流子传输，并在水溶液中进行光催化氮还原（NRR）反应。由于电喷雾气体中的O₂浓度较低，微秒内在Zn/PbO/PC-Zn/MAPbBr₃表面实现Zn-氧空位（Zn-OVs）的共掺杂。通过光电子能谱（XPS）和电子顺磁共振（EPR）技术表征，证实了Zn/PbO/PC-Zn/MAPbBr₃异质结表面OVs的存在；X射线吸收精细结构（XAFS）分析揭示了表面Zn元素的配位环境、电子结构、配位数等信息；还确认Zn均价态为+1.5，并与OVs共存且毗邻，说明Zn的4s轨道存在部分活跃电子用以增强Zn原子光催化固氮反应。该工作通过电喷雾合成，快速获得了水相稳定的钙钛矿量子点异质结材料，并首次探索了其在NRR反应中的应用。

2. 进而，我们基于金属元素掺杂对光催化材料性能提升的重要前景，进一步掺杂了不同价态的过渡金属Pt（Pt^II、Pt^IV）元素，采用电喷雾微滴法一步快速合成了PC和PbO共包覆Pt-Zn共掺杂有机-无机杂化钙钛矿量子点异质结（Pt^II/Zn/PbO/PC-Zn/MAPbBr₃和Pt^IV/Zn/PbO/PC-Zn/MAPbBr₃），用以调控Pt的d轨道电子，进而提高缺电子Pt^IV/Zn/PbO/PC-Zn/MAPbBr₃钙钛矿量子点异质结的光催化固氮产率。与低价态Pt^II掺杂材料（Pt^II/Zn/PbO）相比，Pt^IV/Zn/PbO形成了更多缺电子位点，对N₂有较强的吸附作用，并且抑制质子的吸附。由于缺电子Pt^IV的d轨道空出更多轨道接纳吸附N₂，进而使激发电子更易向N₂反π键转移。缺电子Pt^IV位点降低了其d带中心，使得d带中心远离费米能级（E_f），抑制了Pt^IV/Zn/PbO/PC-Zn/MAPbBr₃钙钛矿量子点异质结的析氢反应（HER）、。通过密度泛函理论（DFT）计算，进一步证实了N₂在缺电子Pt^IV活性位点处比氢原子更优先吸附。该部分工作，进一步提升和拓展了钙钛矿量子点材料在光催化反应领域的应用。

3. 在前面的工作中我们均是通过调节过渡金属局域电子态进而增强催化性能，受此启发在第三个工作中，我们利用硫的多价态特点，短时间内修饰TiO₂表面电子结构，从而增强其光催化析氧（OER）性能。虽然利用电喷雾合成方法在短时间内即可完成材料的合成，但是在快速合成过程中，难于精准控制材料所暴露的催化晶面，不利于催化性能的精准调控。因此，在第三部分工作中，我们利用水热合成法，获得了较为规则的四方晶系金红石TiO₂纳米棒；在退火过程中，晶面部分Ti原子处的C元素逃逸，留下Ti空位（TiVs-TiO₂）。进而，利用S、H₂S、CS₂的不同挥发特性进行气相沉积。由于S原子比Ti原子的半径小，易掺杂到Ti空位处，从而与O离子结合，构造不同S元素掺杂的TiO₂（S-TiO₂、HS-TiO₂、CS₂-TiO₂），进而调节邻近Ti原子的外层电子态。通过DFT计算发现TiVs-TiO₂、S-TiO₂、HS-TiO₂、CS₂-TiO₂中S元素邻近Ti原子的Bader电荷分别为+2.05 e、、+2.08 e、+2.09 e和+2.15 e。实验证明，该方法实现了邻近Ti原子外层电子的精准调控，使得CS₂-TiO₂表现出最为优异的OER催化性能，在不改变TiO₂光吸收的条件下，使CS₂-TiO₂达到纯TiO₂光电催化效率理论值的83 %。该部分工作拓展了非金属元素掺杂半导体催化材料在光催化反应中的应用。

With the rapid development of the modern society, the world is facing the dual crises of the energy and environment. Therefore, it is imperative to exploit renewable energy sources for the long-termed development of the society. Semiconductor photocatalytic reaction can directly transform solar energy into clean chemical energy, which is considered as a effective way to solve the crises of environmental pollution and energy. This thesis is aimed at the development of semiconductor photocatalysts for fast and efficient synthesis. Based on the excellent photocatalysis properties of perovskite quantum dots and correlation semiconductor, a comprehensive research on fast synthesis, material characterizations and the applications on photocatalytic reactions has been employed. Herein, a water-resistant organic-inorganic hybrid perovskites quantum dots (OIP QDs) heterojunction photocatalyst was rapidly prepared by one-step electrospray ionization (ESI)-based microdroplet synthesis in microseconds, which has good stability and merits uniformly scatter in the water. The the electronic properties were manipulated by oxygen vacancies and highly-charged transition metal elements. Therefore, the photocatalytic NRR catalyzed by organic-inorganic hybrid perovskites was promoted in the aqueous phase. In addition, to further regulate the microstruce precisely, the local electronic structure of adjacent Ti atoms is regulated by variable valence of S element indirectly. The photocatalytic oxygen evolution with semiconductor TiO₂ was therefore enhanced. The present thesis is constructive for understanding the structure and photocatalytic properties of the semiconductor materials, expanding their applications on green synthesis. This thesis comprises several sections as following:

First, water-resistant polycarbonate-part-encapsulated Zn-doped PbO-MAPbBr₃ (Zn/PbO/PC-Zn/MAPbBr₃) Type ? heterojunction was rapidly synthesized by one-step electrospray ionization (ESI)-based microdroplet synthesis. This facilitated efficient electron transfer from internal heterojunction interface of Zn/MAPbBr₃ perovskites quantum dots (PQDs) to surface Zn/PbO and achieved photocatalytic N₂ reduction reaction in aqueous phase. Simultaneously, the oxygen level in the mixture was low, which fabricated the codope of Zn-oxygen vacancies (Zn-OVs) on surface of Zn/PbO-Zn/MAPbBr₃ heterojunction. This was successfully confirmed by X-ray photoemission spectroscopy (XPS) and electron paramagnetic resonance (EPR) spectra. The atomic dispersion, electronic structure and coordination environment of Zn element were further examined by X-ray absorption fine structures (XAFS). The Zn element valence was +1.5, which adjoins to OVs and changes the electron filling of Zn-4s orbital to enhcene photocatalytic NRR of Zn/PbO-Zn/MAPbBr₃ heterojunction. Thus, organic?inorganic hybrid PQDs was simply prepared through one-step electrospray and were firstly applied to photocatalytic NRR in aqueous phase without sacrificial agents added.

Subsequently, considering the photocatalytic performance can be improved by doping with metal elements, the organic inorganic hybrid PQDs doped by transition metal of Pt (Pt^II and Pt^IV) element were synthesized. By one-step ESI microdroplet synthesis, the polycarbonate and PbO co-encapsulated Zn-Pt co-doped organic?inorganic hybrid PQDs (Pt^II/Zn/PbO/PC-Zn/MAPbBr₃ and Pt^IV/Zn/PbO/PC-Zn/MAPbBr₃) were rapidly and simply abtained. The Pt^IV metal atom was positively charged with high-valence states, which improved electron delocalization of Pt^IV d-orbitals for the high yield of photocatalytic NRR. Compared to lower valent Pt^II-doped materials (Pt^II/Zn/PbO), the Pt^IV/Zn/PbO species created electron-deficient sites with strong affinity toward N₂ and to suppress H adsorption. The active sites of electron-deficient d-orbital of Pt atoms provided more vacant orbits to nitrogen adsorption, which can inject excited electrons into empty π of N₂. While with stronger metal-N₂ interaction, Pt^IV is favored to adsorb N₂ over H to enhance NRR activities because the Pt^IV d-band states were far from the Fermi level (E_f). Thus, the active site of Pt^IV tends to adsorb N₂, which suppresses HER to increase NRR efficiency. The preferential N₂ adsorption over H atom at electron deficient sites was further confirmed by the density functional theory (DFT) calculations. This work initiates and develops the application of OIP QDs into photocatalytic NRR.

Finally, the surface electron structure of TiO₂ was modified by the polyvalent state of sulfur element in a short time, which can enhance its photocatalytic oxygen evolution (OER) performance. Although ESI-based microdroplet synthesis can synthesis the nanocatalyst rapidly, the precise regulation of microstructure is still hard to be achieved. In this part, for the precise regulation of microstructures, tetragonal rutile TiO₂ nanorods were synthesized by the hydrothermal synthesis method. During the annealing process, C element escaped from the position of Ti atoms on the crystal plane, leaving the Ti vacancy (TiVs-TiO₂). Furthermore, the volatile S, H₂S and CS₂ were utilized for the vapor deposition. Given the radius of S atom is smaller than that of Ti atom, S is easy to be doped into the Ti vacancy. This facilitates the combining of S with O ion to construct doped TiO₂ with different S elements (S-TiO₂、HS-TiO₂、CS₂-TiO₂), adjusting the outer electronic states of adjacent Ti atoms. Confirmed by DFT calculations, Bader charge of adjacent Ti atom to S in TiVs-TiO₂, S-TiO₂, HS-TiO₂ and CS₂-TiO₂ were +2.05 e, +2.08 e, +2.09 e and +2.15 e, respectively. As demonstrated by experimental results, CS₂-TiO₂ has the optimal OER performance, and the photocatalytic efficiency of CS₂-TiO₂ reaches 83 % of the theoretical value of pure TiO₂, without changing the TiO₂ light absorption. This work expands the applications of non-metallic element doped semiconductor materials in photocatalytic reactions.