摘 要
化石燃料的大量使用，排放出过量 CO 2 引发了全球变暖等环境问题。如何减少 CO 2
的排放是目前要解决的关键问题。光催化还原 CO 2 技术能够利用太阳光驱动光催化还原
大气中的 CO 2 得到可再生碳氢燃料，将其作为能源载体，可实现碳的循环利用，在解决
环境问题同时还能够缓解能源危机，是助力碳达峰、碳中和的一项变革性技术。光催化
还原 CO 2 技术的关键是高效光催化剂的设计和制备，其核心在于解决可见光响应差、光
腐蚀及电子-空穴复合率高等问题。ZnS 和 CdS 具有相似的晶格结构、配位模式、相近
的原子半径，形成的 Zn x Cd 1-x S 固溶体具有带隙可调控，可见光响应及催化活性优异等
优点，被广泛应用于光催化转化领域。本文以 Zn x Cd 1-x S 为研究目标，通过能带调控、
形貌结构调控及构建异质结三种方法对其进行改性，从光吸收效率、表面反应效率、光
生电子-空穴分离效率三方面对光催化性能进行研究。同时研究了带隙、形貌、异质结
对光催化还原 CO 2 过程的影响。具体研究内容如下：
（1）采用溶剂法以 CdCl 2 和 ZnCl 2 为镉源和锌源，硫脲为硫源，柠檬酸钠为形貌导
向剂，制备得到 ZnS、Zn 0.2 Cd 0.8 S、Zn 0.5 Cd 0.5 S、Zn 0.8 Cd 0.2 S 和 CdS。利用紫外-可见分光
光度计、荧光、电化学工作站等测试表征分析样品的各项性能。研究发现可见光吸收效
率的提高可以大大提高光催化剂的催化活性。另外，采用溶剂法和水热法制备得到 F-
ZnCdS 和 C-ZnCdS。通过扫描电镜、太赫兹、氮气吸脱附、CO 2 化学吸脱附等测试分析
两种样品的性能。结果表明，F-ZnCdS 具有良好的纳米片组成的花状结构，较大的比表
面积（37 m 2 ∙g -1 ），优异的光利用率，及更优异的甲醇产率（239.6 µmol∙g -1 ∙h -1 ）。
（2）采用原位自组装方法制备得到 F-ZnCdS/CN 复合催化剂，通过控制 g-C 3 N 4 占
比与 F-ZnCdS 复合得到了 F-ZnCdS/CN10%、F-ZnCdS/CN20%、F-ZnCdS/CN30%、F-
ZnCdS/CN40%、F-ZnCdS/CN50%五种样品。采用紫外-可见分光光度计、荧光、电化学
工作站、光催化反应等测试分析其性能。研究表明 F-ZnCdS 与 g-C 3 N 4 成功复合构建了Ⅱ
型异质结，进而提高了催化剂的光生电子空穴利用率。其中，F-ZnCdS/CN20%样品具
有优异的催化性能，比表面积为 45 m 2 ∙g -1 ，光电流密度为 3.25 µA∙cm -2 ，甲醇产率达到
了 700.5 μmol∙g -1 ∙h -1 ，是纯 Zn 0.2 Cd 0.8 S 的 2.92 倍。此外，F-ZnCdS/CN20%在三次回收重
复实验后活性保持在 98%左右，表现出良好的光催化稳定性。

ABSTRACT
The massive use of fossil fuels and the emission of excessive CO 2 have caused
environmental problems such as global warming. Photocatalytic CO 2 reduction technology can
use sunlight to drive the photocatalytic reduction of atmospheric CO 2 to obtain renewable
hydrocarbon fuel, which can be used as an energy carrier to realize the recycling of carbon and
solve environmental problems while alleviating the energy crisis, and is a transformative
technology to help achieve carbon peaking and carbon neutrality. The key of photocatalytic CO 2
reduction technology is the design and preparation of high-efficiency photocatalysts, the core of
which is to solve the problems of poor visible light response, photocorrosion and high electron-
hole complex rate, etc. ZnS and CdS have similar lattice structure, coordination mode and similar
atomic radius, forming Zn x Cd 1-x S solid solution with adjustable band gap, excellent visible light
response and catalytic activity, which is widely used in the field of photocatalytic conversion.
The Zn x Cd 1-x S solid solution is widely used in the field of photocatalytic conversion. In this paper,
Zn x Cd 1-x S was modified by three methods, namely, band gap modulation, morphological
structure modulation and heterojunction construction, and its photocatalytic performance was
investigated in terms of light absorption efficiency, surface reaction efficiency and photo-
generated electron-hole separation efficiency. The effects of band gap, morphology and
heterojunction on the photocatalytic reduction of CO 2 were also investigated. The details of the
study are as follows:
(1) ZnS, Zn 0.2 Cd 0.8 S, Zn 0.5 Cd 0.5 S, Zn 0.8 Cd 0.2 S and CdS samples were prepared by the solvent
method using CdCl 2 and ZnCl 2 as the cadmium and zinc sources, thiourea as the sulfur source,
and sodium citrate as the morphology guide, and by regulating the molar ratio of added zinc and
cadmium. The UV-Vis spectrophotometer, fluorescence and electrochemical workstation were
used to test and characterize and analyze the various properties of the Zn x Cd 1-x S samples. The
analysis revealed that the catalytic activity of the catalysts was improved by increasing the visible
light absorption efficiency. In addition, F-ZnCdS and C-ZnCdS were obtained by two preparation
methods, solvent method and hydrothermal method, and the properties of both samples were
analyzed by scanning electron microscopy, terahertz, nitrogen adsorption and desorption, and
CO 2 chemical adsorption and desorption tests. The results show that F-ZnCdS has a good flower-
like structure composed of nanosheets, a larger specific surface area (37 m 2 ∙g -1 ) and excellent
light utilization, and a more excellent methanol yield (239.6 µmol∙g -1 ∙h -1 ).
(2) In this paper, F-ZnCdS/CN composite catalysts were prepared by an in situ self-assembly
method, and five samples of F-ZnCdS/CN10%、F-ZnCdS/CN20%、F-ZnCdS/CN30%、F-
ZnCdS/CN40%、F-ZnCdS/CN50% were obtained by controlling the percentage of g-C 3 N 4
compounded with F-ZnCdS. The performance was analyzed by UV-Vis spectrophotometer,
fluorescence, electrochemical workstation, and photocatalytic reaction tests. It was further found
that the successful compounding of F-ZnCdS with g-C 3 N 4 constructed type II heterojunctions
improved the photogenerated electron-hole utilization of the catalysts. The results show that one
of the F-ZnCdS/CN20% samples has excellent catalytic performance with a specific surface area
of 45 m 2 ∙g -1 , a photocurrent density of 3.25 µA∙cm -2 , and a methanol yield of 700.5 μmol∙g -1 ∙h -1
which is 2.92 times that of pure Zn 0.2 Cd 0.8 S. In addition, the activity of F-ZnCdS/CN20% was
maintained at about 98% after three recovery replicate experiments, showing good photocatalytic
stability.