Team:ShanghaitechChina/Proof
Detailed Proof
a. We, first, need to obtain a suitable nanomaterial, CdS, that absorbs solar energy and convert it into electrons. The detailed synthesis and characterization data is shown in our webpage Nanomaterials Session for further information. Some key data are reproduced below.
Synthesis and Characterization
Results
Synthesis and Characterization of CdS Nanorods
We synthesized CdS nanorods following a procedure adapted from a previously published protocol[1]. The synthesis procedure mainly contains two steps: synthesis of CdS seeds, followed by growth of CdS nanorods using CdS nanoparticles as nuclei.
Figure 3. Solutions of CdS nanoparticle seeds in TOP (left), CdS NRs in toluene (right)
Characterization of UV-Vis was performed to calculate the concentration of CdS seed in TOP solution and CdS nanorod in toluene solution. Also, PL spectrum of CdS NRs in toluene was collected to investigate the emission attribute of the nanorod. TEM image of the nanorods was acquired to study the shape and size distribution.
Figure 4. Result of CdS NRs ligand exchange experiments.
A ligand exchange experiment was performed and the result is shown in Figure 4
Figure 5. UV-Vis spectra of CdS seeds in TOP (A) and CdS nanorods in toluene (B);. Photoluminescence Spectrum of CdS nanorods in toluene (C).
The concentration of CdS seeds and CdS NR products were determined by using the UV-Vis spectrometer (Fig. 5 A, B). The peak shown in PL spectrum (Fig. 5 C) matches the absorption peak of the UV-Vis spectra, which thus proves the synthesis of CdS NRs.
Figure 6. TEM images of CdS NRs (A) and size distribution of CdS NRs (B). Note: 100 NRs in total were measured to determine the size distribution. The NRs thus measured have an average diameter of 3.93±0.57nm and average length of 66.81±6.74nm.
TEM confirms that synthesized products show nanorod feature, with an average diameter of 3.93±0.57nm and average length of 66.81±6.74nm.
