Visible light catalysis-assisted assembly of Ni(h)-QD hollow nanospheres in situ via hydrogen bubbles.
Hollow spheres are one of the most promising micro-/nanostructures because of their unique performance in diverse applications. Templates, surfactants, and structure-directing agents are often used to control the sizes and morphologies of hollow spheres. In this Article, we describe a simple method based on visible light catalysis for preparing hollow nanospheres from CdE (E = Te, Se, and S) quantum dots (QDs) and nickel (Ni(2+)) salts in aqueous media. In contrast to the well-developed traditional approaches, the hollow nanospheres of QDs are formed in situ by the photogeneration of hydrogen (H2) gas bubbles at room temperature. Each component, that is, the QDs, metal ions, ascorbic acid (H2A), and visible light, is essential for the formation of hollow nanospheres. The quality of the hollow nanospheres depends on the pH, metal ions, and wavelength and intensity of visible light used. Of the various metal ions investigated, including Cu(+), Cu(2+), Fe(2+), Fe(3+), Ni(2+), Mn(2+), RuCl5(2-), Ag(+), and PtCl4(2-), Ni(2+) ions showed the best ability to generate H2 and hollow-structured nanospheres under visible light irradiation. The average diameter and shell thickness of the nanospheres ranged from 10 to 20 nm and from 3 to 6 nm, respectively, which are values rarely reported in the literature. Studies using high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), inductively coupled plasma-mass spectroscopy (ICP-AES), and steady-state and time-resolved spectroscopy revealed the chemical nature of the hollow nanospheres. Additionally, the hollow-structured nanospheres exhibit excellent photocatalytic activity and stability for the generation of H2 with a rate constant of 21 μmol h(-1) mg(-1) and a turnover number (TON) of 137,500 or 30,250 for CdTe QDs or nickel, respectively, under visible light irradiation for 42 h.
Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry & University of Chinese Academy of Sciences, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
Zhi-Jun
ZJ
Li
Xiang-Bing
XB
Fan
Xu-Bing
XB
Li
Jia-Xin
JX
Li
Chen
C
Ye
Jiu-Ju
JJ
Wang
Shan
S
Yu
Cheng-Bo
CB
Li
Yu-Ji
YJ
Gao
Qing-Yuan
QY
Meng
Chen-Ho
CH
Tung
Li-Zhu
LZ
Wu
D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D008027:Light; D046529:Microscopy, Electron, Transmission; D054118:Nanospheres / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D045663:Quantum Dots / Q000737:chemistry*; D012995:Solubility; D013054:Spectrophotometry, Atomic; D013499:Surface Properties; D013691:Tellurium / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
D014867:Water; D009532:Nickel; D006859:Hydrogen; D015097:3-Mercaptopropionic Acid; D013691:Tellurium