Quantum dots-sensitized solar cell (QDSSC) is one of the third generation solar cell that is
the most promising low cost, easy to manufacture and highly efficient solar cell. Compared to Dyesensitized
solar cell (DSSC), quantum dots (QDs) of QDSSC has a narrow bandgap and possess
excellent properties such as tunable band gaps, strong light absorption and high multiple electron
generation. Titanium dioxide or titania (TiO2) is an oxides semiconductor material that is frequently
used as a photoanode in this photovoltaic system due to high stability under visible light illumination.
TiO2 is also known as a good photocatalyst and an excellent choice in environmental purification. The
efficiencies of electron injection and light harvesting in QDSSC are affected by the nature, size
morphology, and quantity of this nanomaterial. In this review, the concept and principles of the
QDSSCs are reviewed. The preparation and fabrication method ofTiO2 electrode in QDSSC are also
discussed. It is worthwhile to know the architecture of TiO2 in order to enhance the efficiency of
QDSSC.
The fabrication of an electrochemical sensor based on an iron oxide/graphene modified glassy carbon electrode (Fe3O4/rGO/GCE) and its simultaneous detection of dopamine (DA) and ascorbic acid (AA) is described here. The Fe3O4/rGO nanocomposite was synthesized via a simple, one step in-situ wet chemical method and characterized by different techniques. The presence of Fe3O4 nanoparticles on the surface of rGO sheets was confirmed by FESEM and TEM images. The electrochemical behavior of Fe3O4/rGO/GCE towards electrocatalytic oxidation of DA was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) analysis. The electrochemical studies revealed that the Fe3O4/rGO/GCE dramatically increased the current response against the DA, due to the synergistic effect emerged between Fe3O4 and rGO. This implies that Fe3O4/rGO/GCE could exhibit excellent electrocatalytic activity and remarkable electron transfer kinetics towards the oxidation of DA. Moreover, the modified sensor electrode portrayed sensitivity and selectivity for simultaneous determination of AA and DA. The observed DPVs response linearly depends on AA and DA concentration in the range of 1-9 mM and 0.5-100 µM, with correlation coefficients of 0.995 and 0.996, respectively. The detection limit of (S/N = 3) was found to be 0.42 and 0.12 µM for AA and DA, respectively.