CHINESE JOURNAL OF CHEMICAL PHYSICS MARCH 31, 2021 ARTICLE Characterization and Visible Light Photocatalytic Activity of Cucurbit[n]urils/CdS-MoS 2 Juan-juan Shi , An-ting Zhao * , Zhang-mei Peng, Li-xia Yang, Chun-tao Zhou College of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China (Dated: Received on December 11, 2020; Accepted on March 15, 2021) In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance, a narrow band gap semiconductor MoS 2 and organic macro- molecular cucurbit[n]urils (Q[n]) were used to modify CdS. Q[n]/CdS-MoS 2 (n=6, 7, 8) composite photocatalysts were synthesized by hydrothermal method. Infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron mi- croscopy, ultraviolet-visible and photoluminescence spectrum were used to characterize the structure, morphology and optical properties of the products, and the catalytic degrada- tion of the solutions of methylene blue, rhodamine B and crystal violet by Q[n]/CdS-MoS 2 composite catalyst was investigated. The results showed that the Q[n] played a regulatory role on the growth and crystallization of CdS-MoS 2 particles, Q[n]/CdS-MoS 2 (n=6, 7, 8) formed flower clusters with petal-like leaves, the flower clusters of petal-like leaves increased the surface area and active sites of the catalyst, the Q[n]/CdS-MoS 2 barrier width decreased, the electron-hole pair separation efficiency was improved in the Q[6]/Cds-MoS 2 . Q[n] makes the electron-hole pair to obtain better separation and migration. The Q[6]/CdS-MoS 2 and Q[7]/CdS-MoS 2 have good photocatalytic activity for methylene blue, and the catalytic process is based on hydroxyl radical principle. Key words: Hydrothermal method, Cadmium sulfide, Narrow band gap, Cucurbit[n]uril, Coordination I. INTRODUCTION CdS has a low direct band gap value and is sensi- tive to visible light, so it is widely used in the study of photocatalyst research [1, 2]. However, under illumina- tion, electron holes generated by cadmium sulfide pho- toelectricity are easy to recombine, affecting its photo- catalytic efficiency [3–5]]. Therefore, in order to inhibit the photoelectron-hole pair recombination in the photo- catalytic process, the introduction of narrow band gap semiconductors or organic compound recombination in CdS is an effective way to improve its photocatalytic performance [6–10]. Narrow band gap semiconductor molybdenum disulfide has an adjustable energy band gap, and the band gap width is 1.2-1.9 eV [11–16]. * Author to whom correspondence should be addressed. E-mail: [email protected]Cao’s group [17] used CdS@MoS 2 to produce hydrogen efficiently under visible light. Hydrogen produced under the condition of 0.30 mmol benzodiazepine substrate was about 53 times higher than the pure CdS nanorod. The pumpkin-shaped macromolecular cucurbit[n]urils (Q[n], [C 6 H 6 O 2 N 4 ] n , n=5-15) has a polar port. Non- polar cavities and positively charged outer wall struc- ture features, can coordinate with metal ions, inclusion and hydrogen bonding [18–27]. Karami and his collab- orators [28] synthesized a new dimer nano-palladium (Q[6]-Pd NPs) catalyst dispersed on the surface of Q[6], which was used for the coupling reaction between aryl- halides and arylboric acid in water-ethanol (1:1), and showed good reactivity and stability. Cucurbit[n]urils is considered as a suitable carrier for the preparation of nanostructured catalysts [29]. In view of this, a series of Q[n]/CdS-MoS 2 composite catalysts were de- signed and synthesized by a hydrothermal method using MoS 2 with narrow band gap and organic macromolec- DOI:10.1063/1674-0068/cjcp2012214 c ⃝2021 Chinese Physical Society
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CHINESE JOURNAL OF CHEMICAL PHYSICS MARCH 31, 2021
ARTICLE
Characterization and Visible Light Photocatalytic Activity of
College of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China
(Dated: Received on December 11, 2020; Accepted on March 15, 2021)
In order to reduce the impact of CdS photogenerated electron-hole recombination on its
photocatalytic performance, a narrow band gap semiconductor MoS2 and organic macro-
molecular cucurbit[n]urils (Q[n]) were used to modify CdS. Q[n]/CdS-MoS2 (n=6, 7, 8)
composite photocatalysts were synthesized by hydrothermal method. Infrared spectroscopy,
X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron mi-
croscopy, ultraviolet-visible and photoluminescence spectrum were used to characterize the
structure, morphology and optical properties of the products, and the catalytic degrada-
tion of the solutions of methylene blue, rhodamine B and crystal violet by Q[n]/CdS-MoS2composite catalyst was investigated. The results showed that the Q[n] played a regulatory
role on the growth and crystallization of CdS-MoS2 particles, Q[n]/CdS-MoS2 (n=6, 7, 8)
formed flower clusters with petal-like leaves, the flower clusters of petal-like leaves increased
the surface area and active sites of the catalyst, the Q[n]/CdS-MoS2 barrier width decreased,
the electron-hole pair separation efficiency was improved in the Q[6]/Cds-MoS2. Q[n] makes
the electron-hole pair to obtain better separation and migration. The Q[6]/CdS-MoS2 and
Q[7]/CdS-MoS2 have good photocatalytic activity for methylene blue, and the catalytic
process is based on hydroxyl radical principle.
Key words: Hydrothermal method, Cadmium sulfide, Narrow band gap, Cucurbit[n]uril,
Coordination
I. INTRODUCTION
CdS has a low direct band gap value and is sensi-
tive to visible light, so it is widely used in the study of
photocatalyst research [1, 2]. However, under illumina-
tion, electron holes generated by cadmium sulfide pho-
toelectricity are easy to recombine, affecting its photo-
catalytic efficiency [3–5]]. Therefore, in order to inhibit
the photoelectron-hole pair recombination in the photo-
catalytic process, the introduction of narrow band gap
semiconductors or organic compound recombination in
CdS is an effective way to improve its photocatalytic
performance [6–10]. Narrow band gap semiconductor
molybdenum disulfide has an adjustable energy band
gap, and the band gap width is 1.2−1.9 eV [11–16].
∗Author to whom correspondence should be addressed. E-mail: