Semiconductor quantum dots,composed of elements from groups Ⅱ-Ⅵ(CdSe,CdTe,CdS,ZnTe,ZnO),Ⅲ-Ⅴ(InAs,GaSb,InP)and Ⅳ(Si,Ge),are nanoscale particles attracting significant research interest.The focus of current studies lies predominantly on Ⅱ-Ⅵ group quantum dots like CdS,CdSe,and CdTe,known for their narrow band gaps and exceptional fluorescent properties intrinsically related to quantum size effects.In this study,a straightforward aqueous reflux method was employed,using thioglycolic acid as a stabilizer,and NaHTe as a Te precursor.Over a period of 3 h,CdTe semiconductor quantum dots of various colors were prepared,addressing and mitigating the issue of oxidation susceptibility during NaHTe transfer.The fluorescence luminescence properties of the product were meticulously analyzed,yielding a series of CdTe quantum dots with an impressive quantum efficiency of 48%.This experimental approach is notable for its simplicity,minimal reagent consumption,and distinct fluorescence characteristics,making it highly operable and replicable.It is well-suited for undergraduate education in inorganic chemistry,instrumental analysis,and comprehensive professional experiments.

A composite electrode of Ni-ferrite/TiOx/Si(111) was synthesized by grafting Ni2+Fe2+Fe3+–LDH–TiCl3 (LDH: Layered Double Hydroxides) on n-Si(111) surface and calcined under 1100°C. Photoelectric research results indicated that the electrode had good photovoltaic effects in an electrolyte solution containing 7.6M HI and 0.05M I2, while platinum plate was used as counter-electrode. The observed photo-voltages (Upv) and photocurrent densities (jpc) of the electrode were at −0.75V and 5.35mA/cm2, respectively. Compared with electrodes of oxidized n-Si(111) crystal and n-Si(111) wafer covered by Ni-ferrites, jpc of the electrode Ni-ferrite/TiOx/Si(111) was increased greatly.

A series of Ni/Fe spinel ferrite overlays with different contents of spinel ferrite were prepared on n-silicon (111) wafers by calcination of Ni2+/Fe2+/Fe3+-LDHs carbonate precursors assembled on n-Si (111) wafers at 900°C. The spinel ferrite overlay was found to improve the photoelectric properties of the silicon crystalline in terms of photovoltage and photocurrent in an electrolyte solution containing 7.6M HI and 0.05M I2. The observed photovoltages (Upv) and photocurrent densities (jpc) of the composite electrodes were enhanced with an increase of the content of spinel ferrite in the overlay.

n-Si(111) surface tailed -C2H5, -C2H4COOH, -C2H2COOH were prepared by the reactions among Si-H to ethyl-Grignard, methyl acrylate and ethyl propionate, and the carboxyls were formed under the existence of trifluoroacetic acid. The composite n-Si(111) electrodes were obtained by depositing Pt nanodots and the photovoltaic characteristics for these electrodes were studied in I-/I-3(-) redox electrolyte. The j-U (photo current density-potential) behaviors of photo-voltage and photocurrent densities to the electrodes under solar illumination varied regularly with groups of -C2H2COOH > -C2H4COOH > -H > -C2H5. The photo-voltage and photocurrent density of the electrode tailed -C2H2COOH were -0.641 V and 5.25 mA/cm(2), respectively, more negative than those of the non-conjugated modification.

n-Si(111) crystalline electrode was modified by carboxyl acid groups and sulfonic groups. The flat band potential (U-fb), relation between flat band potential and the carbon numbers to the modified samples and relation between photocurrent density and potential of the modified electrodes were studied. ATR-IR spectra and XPS analysis show that the organic compounds were connected to n-Si(111) wafer by Si-C bond. Calculation indicates that the surface modification ratio increased with the carbon number of organic groups decreased. Mott-Schottky plots gives the flat band potential of the samples to shift to negative positions with the carbon number decreased in both of the two different systems and the flat band potential of the sample with the group of -(CH2)(3)SO3H reaches to -0.82 V, which is more negative than reported, and the flat band potential of all the samples in this paper are more negative than the sample with methyl group [B. Ashish, N.S. Lewis, J. Phys. Chem. B 102 (1998) 1067; S. Takabayashi, M. Ohashi, K. Mashima, Y. Liu, S. Yamazaki, Y. Nakato, Langmuir 21 (2005) 8832]. The photocurrent and photovoltage of the modifications are stable enough under solar illumination for a long time. (c) 2007 Elsevier B.V. All rights reserved.

A platinum complex, Pt-4 ( OCOCH3), ( OCOCH = CH2)(4),was synthesized by the reaction of Pt-4(OCOCH3)(8) with acrylic acid in dichloromethane as solvent, four equatorial acetate ligands in Pt-4 ( OCOCH3)(8) were selectively replaced by acrylates. At the same time, n-Si ( 111) crystalline was modified by this complex and many island-like particles were formed on the silicon wafer. Characterizations of XPS as well as SEM and FTIR spectrum reveal that the platinum clusters close to the wafer covalently connected to silicon in Si-C bonds and the assembly is stable at a high temperture and in some acidic solutions. Keywords Platinum complex; Single crystal; n-Si ( 111) crystalline; Grafting; Island-like particle.