可见光响应三元ZnxCd1-xS RGO复合光催化剂的可控合成及光催化产氢性能研究

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可见光响应三元ZnxCd1-xS/RGO复合光催

化剂的可控合成及光催化产氢性能研究

摘要

随着全球范围环境污染和能源危机的日趋严重，环境治理和新能源开发成为全

人类社会共同关注和急需解决的问题。半导体光催化技术在解决环境污染和能源再

生方面具有潜在能力。特别是利用太阳能多相光催化降解污染物以及分解水制氢技

术，因其能直接利用太阳能且体系简单，日益受到广泛关注。但是TiO2、ZnO和

ZnS等研究较多的光催化剂都是宽禁带半导体材料，只能被紫外光所激发。紫外光

只占太阳光总能量的大约5%，太阳光能量主要集中在400-700nm的可见光范围，达

太阳光总能量的约43%。因此，研究和开发高效、稳定的可见光催化剂有望实现太

阳能光催化技术的产业化应用，在解决环境污染治理和清洁能源生产方面取得突破

性进展。本论文设计合成了ZnxCd1-xS纳米棒/石墨烯纳米片组成的一维/二维复合型

可见光催化剂，利用TEM、XRD、XPS等测试手段对产物的成分、结构、维度、

暴露晶面等结构信息进行了表征，利用UV-Vis和PL光谱表征了产物的可见光吸收

光致发光等光学性质，探索了ZnxCd1-xS纳米棒/石墨烯复合材料作为可见光催化剂

降解有机污染物及光解水产氢性能。

本论文具体研究内容及重要结论如下：

1. ZnxCd1-xS催化剂的可控合成及性质研究

以Zn(DDTC)2和Cd(DDTC)2为前驱体，通过热分解法一步合成了ZnxCd1-xS固溶

体，通过调节前驱体用量（Zn：Cd）对产物结构、形貌以及光学性质进行调控。

利用TEM、XPS、XRD、UV-Vis、PL等测试手段对其进行了表征。实验结果表明

长径比和带隙能均随着Zn含量的增大而增大，晶胞参数随着Zn：Cd比例的变化呈

现线性变化且符合维加德定律。当Z n：C d前驱体比例为1：1时，得到的

Zn0.5Cd0.5S纳米棒具有最佳的长径比和带隙能，相对于其他比例的ZnxCd1-xS纳米晶

体表现出了最强的光电响应特性，Zn0.5Cd0.5S的光生电流密度是Zn0.875Cd0.125S的25倍

2. 可见光催化剂Zn0.5Cd0.5S/RGO的设计合成及光催化性能研究

采用一步热分解法合成了ZnxCd1-xS/RGO复合可见光催化剂，通过调节前驱体

用量及石墨烯含量对产物结构、形貌以及光催化性能进行了调控，通过 TEM、

XPS、PL、XRD等测试手段对样品进行了表征。通过TEM测试观察到ZnxCd1-xS纳

米棒均匀的分散在石墨烯薄膜上。对不同RGO含量的ZnxCd1-xS/RGO光催化剂的光

催化研究结果表明，RGO含量为2wt%时，复合光催化剂的可见光催化活性最高。

Zn0.5Cd0.5S和Zn0.5Cd0.5S/2%RGO的可见光降解和可见光解水的循环性对比实验，结

果显示Zn0.5Cd0.5S/2%RGO具有很高的光催化稳定性。

具有一维/二维复合结构的Zn0 . 5

Cd0 .5

S/2%RGO复合可见光催化剂较单纯的

Zn0.5Cd0.5S具有更高的稳定性和光催化活性。这主要是因为，石墨烯完美的二维结

构和高的比表面积提高了光催化剂的分散性和稳定性；而其优异的导电性加快了光

生电子的迁移速率，抑制了光生电子和空穴的复合，从而很大程度的提高了可见光

催化效率。该结果为开发高效、可见光响应的光催化剂提供了重要依据。

关键词：可见光响应金属硫化物固溶体石墨烯一维/二维复合

ABSTRACT

W i t h t h e i n c r e a s i n g l y s e r i o u s e n v i r o n m e n t a l p o l l u t i o n a n d e n e r g y c r i s i s ,

environmental management and developing new energy has become common concern

of all mankind and urgent problems. The semiconductor photocatalytic technology has

potential ability in solving environmental pollution and energy regeneration. Especially

in use of solar energy for heterogeneous photocatalytic degradation of pollutants and

decomposition of water into hydrogen technology has attracted wide concern, because

solar energy is utilized directly and the system is simple. But more studied potocatalysts

s u c h a s T i O

2 a n d Z n S a r e w i d e b a n d g a p s e m i c o n d u c t o r m a t e r i a l s , a n d o n l y c a n b e

e x c i t e d b y u l t r a v i o l e t l i g h t , w h i c h i s o n l y 5 % a m o n g t h e s o l a r e n e r g y. T h e r a t i o o f

visible light is 43%. So the development of visible-light driven high performance

p h o t o - c a t a l y s t i s a b r e a k t h r o u g h t o r e a l i z e t h e i n d u s t r i a l i z a t i o n o f s o l a r e n e r g y

photocatalytic technology in solving the environmental pollution and cleaning energy

production. The thesis designed and synthesized a 1D/2D structure of ZnxCd1- x

S/RGO

v i s i b l e - l i g h t c o m p o s i t e p h o t o c a t a l y s t. T h e s a m p l e wa s c h a r a c t e r i z e d b y t r a n s m i s s i o n

electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction

( X R D ), U V - V i s a b s o r p t i o n s p e c t r o s c o p y ( U V - V i s ) a n d P L a n d t h e o t h e r t e s t

methods. Explores the Zn

xCd1-xS/RGO composites as visible light catalyst degradation

of organic pollutants and hydrogen photolysis aquatic product performance

The research content and important conclusions of this paper are as follows:

1. Controllable synthesis and optical properties of ZnxCd1-xS photocatalyst

ZnxC d

1 - x

S s o l i d s o l u t i o n w a s s u c c e s s f u l l y s y n t h e s i z e d v i s a o n e -s t e p t h e r m a l

d e c o m p o s i t i o n m e t h o d b y u s i n g Z n ( D D T C )

2 a n d C d ( D D T C )

2 a s p r e c u r s o r . T h e

structure, morphology and performance of ZnxC d

1 - x

S so li d s ol u ti on w er e a d ju s te d b y

c h a n g i n g t h e d o s a g e o f p r e c u r s o rs ( Z n : C d ). T h e s a m p l e wa s c h a r a c t e r i z e d b y

t r a n s m i s s i o n e l e c t r o n m i c r o s c o p e ( T E M ), X - r a y p h o t o e l e c t r o n s p e c t r o s c o p y ( X P S ) ,

X - r a y d i f f r a c t i o n ( X R D ) , U V - V i s a b s o r p t i o n s p e c t r o s c o p y ( U V - V i s )

a n d P L a n d t h e o t h e r t e s t m e t h o d s. T h e r e s u l t s i n d i c a t e d t h a t t h e a s p e c t r a t i o a n d

b a n d g a p e n e r g y o f t h e n a n o c r y s t a l s i n c r e a s e d w i t h i n c r e a s i n g o f Z n c o n t e n t .

A linear c ompression in both the a and c axes was observed throughout the range of

compositions (from x =0.125 to x =0.875), consistent with the expectations for Vegard’s

law behavior. Zn0.5

Cd0 .5

S nanorods with suitable band gap and aspect ratio display the

highest photoresponse. The photocurrent density of Zn0.5Cd0.5S is even 25 times as high

as that of Zn0.875Cd0.125S.

2 . T h e s y n t h e s i s a n d p e r f o r m a n c e o f t h e v i s i b l e - l i g h t d r i v e n

ZnxCd1-xS/RGO

ZnxCd1 -x

S/RGO visible-light composite photocatalyst was synthesized by a thermal

decomposition method. The samples were characterized by TEM, XPS, XRD and the

o t h e r   t e s t   m e t h o d s . T h e   Z n
xC d
1 - x
S nanorods were evenly dispersed on the graphene
o b s e r v e d   b y   T E M .   W i t h   d i f f e r e n t   c o n t e n t   o f   R G O   Z n
xC d
1 - x
S / R G O   v i s i b l e - l i g h t
composite photocatalyst, the research results show that the Zn
0 . 5
Cd0 . 5
S/2wt%RGO has
t h e   h i g h e s t   p h o t o c a t a l y t i c   a c t i v i t y .   W i t h   d i f f e r e n t   Z n : C d   r a t i o   o f
Z n
xC d
1 - x
S / 2 % R G O ,   t h e   e x p e r i m e n t a l   r e s u l t s   a l s o   s h o w s   t h a t   p h o t o c a t a l y t i c   e f f e c t   o f
Z n
0 . 5
C d
0 . 5
S / 2 w t % R G O   i s   b e s t .   A n d   t h e   c y c l i c   e x p e r i m e n t s   o f   Z n
0 . 5
C d
0 . 5
S   a n d
Z n
0 . 5
C d
0 . 5
S / 2 w t % R G O   s h o w s   t h a t   Z n
0 . 5
C d
0 . 5
S / 2 w t % R G O   h a s   h i g h e r   s t a b i l i t y   t h a n
Zn0.5Cd0.5S. 
T h e   1 D / 2 D   s t r u c t u r ed  Z n
0 . 5
C d
0 . 5
S / 2 w t % R G O   v i s i b l e - l i g h t- d r i v e n  p h o t o c a t a l y s t
exhibited higher stability and catalytic activity than Zn
0.5Cd0.5S. This is mainly because
t h a t  t h e  p e r f e c t   t w o - d i m e n s i o n a l   s t r u c t u r e   a n d   h i g h   s p e c i f i c   s u r f a c e   a r e a
o f   R G O  i n c r e a s e d   t h e   d i s p e r s i b i l i t y   a n d   s t a b i l i t y   o f   Z n
0 . 5
C d
0 . 5
S nanorods. And the
e x c e l l e n t   c o n d u c t i v i t y  o f   R G O  s p e d   u p   t h e   t r a n s f e r   r a t e   o f   t h e
e l e c t r o ns  a n d   i m p r o v e d  t h e  s e p a r a t i o n  e f f i c i e n c y   o f  p h o t og e n e r a t e d  e l e c t r o n s   a n d
h o l e s.  T h u s   g r e a t l y   i m p r o v e   t h e   v i s i b l e   l i g h t  p h o t oc a t a l y t i c   e f f i c i e n c y .   T h e   r e s u l t s
provide an important basis for the development of high efficiency and visible light
response photocatalyst.
K e y   W o r d :   v i s i b l e - l i g h t - d r i v e n ,   m e t a l   s u l f i d e ,   s o l i d   s o l u t i o n ,
graphene, 1D/2D composite
目  录
摘要
ABSTRACT
第一章 绪论.....................................................................................................................1
1.1 引言........................................................................................................................1
1.2 半导体可见光催化剂............................................................................................2
1.2.1 
半导体光催化反应机理
.................................................................................2
1.2.2 
半导体可见光催化剂的种类
.........................................................................3
1.2.3 
影响半导体可见光催化剂性能的因素
.........................................................4

1.3 金属硫化物可见光催化剂....................................................................................5
1.4 提高金属硫化物可见光催化活性的方法............................................................6
1.4.1 
贵金属修饰
.....................................................................................................6
1.4.2 
离子掺杂
.........................................................................................................7
1.4.3 
复合半导体
.....................................................................................................7
1.4.4 
硫化物固溶体
.................................................................................................7
1.4.5 
与石墨烯复合
.................................................................................................8
1.5 研究意义、研究内容及创新点..........................................................................10
第二章 实验装置、药品以及表征仪器.......................................................................11
2.1 实验药品及仪器..................................................................................................11
2.1.1 
实验试剂
.......................................................................................................11
2.1.2 
实验仪器
.......................................................................................................11
2.2 样品的制备..........................................................................................................12
2.2.1 
硫化物前驱体的制备
...................................................................................12
2.2.2 
氧化石墨烯（
GO
）的制备
.........................................................................13
2.2.3 ZnxCd1-xS
的可控合成
....................................................................................13
2.2.4 ZnxCd1-xS/RGO
复合可见光催化剂的合成
..................................................14
2.3 可见光催化反应..................................................................................................14
2.3.1 
可见光催化降解亚甲基蓝
...........................................................................15
2.3.2 
可见光催化水分解制氢
...............................................................................15
2.4 表征方法..............................................................................................................15
第三章 ZNXCD1-XS的可控合成及表征........................................................................16
3.1 形貌及组成..........................................................................................................16
3.2 光学性质..............................................................................................................18
3.3 光电性质..............................................................................................................21
3.4本章小结...............................................................................................................23
第四章 ZN0.5CD0.5S/RGO复合可见光催化剂的合成及光催化性能研究..................24
4.1 形貌及组成表征..................................................................................................24
4.2 催化剂的表面改性..............................................................................................29
4.3 ZN0.5CD0.5S/RGO降解有机染料亚甲基蓝.........................................................30
4.3.1 
亚甲基蓝标准曲线
.......................................................................................30
4.3.2 RGO
含量对降解效率的影响
......................................................................31
4.3.3 Zn0.5Cd0.5S/RGO
降解亚甲基蓝稳定性研究
.........................................................31
4.3.4 Zn0.5Cd0.5S/RGO
降解亚甲基蓝的机理
........................................................32
4.4 ZN0.5CD0.5S/RGO可见光催化分解水产氢.........................................................33
4.4.1 
氢气标准曲线
...............................................................................................33
4.4.2 RGO
含量对光解水产氢效率的影响
..........................................................34
4.4.3 
光催化剂可见光解水的稳定性研究
...........................................................35
4.4.4 Zn
：
Cd
比例对
ZnxCd1-xS/2wt%RGO
可见光催化性能的影响
....................37
4.4.5 Zn0.5Cd0.5S/RGO
可见光分解水产氢机理
....................................................39

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摘要：

可见光响应三元ZnxCd1-xS/RGO复合光催化剂的可控合成及光催化产氢性能研究摘要随着全球范围环境污染和能源危机的日趋严重，环境治理和新能源开发成为全人类社会共同关注和急需解决的问题。半导体光催化技术在解决环境污染和能源再生方面具有潜在能力。特别是利用太阳能多相光催化降解污染物以及分解水制氢技术，因其能直接利用太阳能且体系简单，日益受到广泛关注。但是TiO2、ZnO和ZnS等研究较多的光催化剂都是宽禁带半导体材料，只能被紫外光所激发。紫外光只占太阳光总能量的大约5%，太阳光能量主要集中在400-700nm的可见光范围，达太阳光总能量的约43%。因此，研究和开发高效、稳定的可见光催化剂有望实...

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