A Dye-Sensitized Solar Cell Using a Composite of PEDOT:PSS and Carbon Derived from Human Hair for a Counter Electrode

Carbon derived from hair is interesting because it has good electrocatalytic activity due to the existence of innate heteroatom dopants especially nitrogen and sulfur. In this study, a carbon catalyst containing high nitrogen contents (9.47 at.%) was fabricated without using any harsh chemicals. Moreover, the carbonization temperature was only 700°C. Carbonized hair/PEDOT:PSS composites (CxP) with varied carbon contents from x = 0.2 to 0.8 g were tested as a counter electrode (CE) for a dye-sensitized solar cell (DSSC). This type of DSSC CE has scarcely been investigated. A DSSC with a C0.6P CE provides the best efficiency (6.54 ± 0.11%) among all composite CEs because it has a high fill factor (FF) and a high short-circuit current density (Jsc). The efficiency of DSSC with C0.6P CE is lower than Pt’s (7.29 ± 0.01%) since the Pt-based DSSC has higher FF and Jsc values. However, C0.6P is still promising as a DSSC CE since it is more cost-effective than Pt

Magnetic and Cytotoxicity Properties of La1−xSrxMnO3(0 ≤ x ≤ 0.5) Nanoparticles Prepared by a Simple Thermal Hydro-Decomposition

This study reports the magnetic and cytotoxicity properties of magnetic nanoparticles of La1−xSrxMnO3(LSMO) withx = 0, 0.1, 0.2, 0.3, 0.4, and 0.5 by a simple thermal decomposition method by using acetate salts of La, Sr, and Mn as starting materials in aqueous solution. To obtain the LSMO nanoparticles, thermal decomposition of the precursor was carried out at the temperatures of 600, 700, 800, and 900 °C for 6 h. The synthesized LSMO nanoparticles were characterized by XRD, FT-IR, TEM, and SEM. Structural characterization shows that the prepared particles consist of two phases of LaMnO3(LMO) and LSMO with crystallite sizes ranging from 20 nm to 87 nm. All the prepared samples have a perovskite structure with transformation from cubic to rhombohedral at thermal decomposition temperature higher than 900 °C in LSMO samples ofx ≤ 0.3. Basic magnetic characteristics such as saturated magnetization (MS) and coercive field (HC) were evaluated by vibrating sample magnetometry at room temperature (20 °C). The samples show paramagnetic behavior for all the samples withx = 0 or LMO, and a superparamagnetic behavior for the other samples havingMSvalues of ~20–47 emu/g and theHCvalues of ~10–40 Oe, depending on the crystallite size and thermal decomposition temperature. Cytotoxicity of the synthesized LSMO nanoparticles was also evaluated with NIH 3T3 cells and the result shows that the synthesized nanoparticles were not toxic to the cells as determined from cell viability in response to the liquid extract of LSMO nanoparticles