ZnO Nanowires as a Promotor of High Photoinduced Efficiency and Voltage Gain for Cathode Battery Recharging

Abstract

In recent years, intensive efforts have been focused on the conversion and storage of solar energy in a single device. In this work, we report the use of ZnO-based electrodes in the form of monolayer or nanowires as a light inducer for battery recharging. Two transition metal complexes of ruthenium(II) and iron(II) are grafted onto the ZnO-based electrode to tune the efficiency of the system. We explore the influence of both the ZnO morphology and nature of the transition metal complex on the light induced voltage and faradaic efficiency toward electrochemical storage. The resulting ZnO-based electrodes have all been found to be electrochemically photoactive and their functionalized ZnO nanowire counterpart has shown the best results. Once the ruthenium complex has been grafted, a high potential gain between dark and illumination conditions of 1.3 V is reached, which is associated with a modest faradaic efficiency of 50%. However, in the presence of the iron complex, a favorable potential gain of 700 mV is obtained and advantageously combined with a faradic efficiency of 100%. These results undoubtedly highlight the remarkable synergy between photoactive ZnO, especially in the form of nanowires, and a redox center allowing it to be applied for a photorechargeable battery device.

Halide Perovskite Materials for Energy Storage Applications

“…Organometallics based on ruthenium and iron are assembled on the ZnO nanowires, producing a voltage increase of 1.3 V when the light is switched on. [ 100 ] Organic boron‐dipyrromethene (BODIPY) dye derivatives are employed to modify boron dipyrromethene polymer; the resulting device exhibits a voltage gain by 0.8 V under light irradiation. [ 101 ] Perylene diimides, [ 102 ] eumelanin [ 103 ] cyanine dendrimers [ 104 ] as well as a number of other dye chromophores [ 105–108 ] are employed to enhance the energy storage performance by effectively absorbing the solar energy.…”

Custom Synthesis of ZnO Nanowires for Efficient Ambient Air-Processed Solar Cells

“…ZnO was chosen as the carrier material of the nanostructure. It is widely used as a functional material in several optoelectronic applications such as light-emitting diodes (LEDs), dye PV cells, − sensors, , thermoelectric devices, transistors, photoelectrodes, , and photo-assisted batteries because it presents a unique combination of functional properties, structural properties, chemical stability, and tunable micro/nanostructure. , In terms of functional properties, semiconducting ZnO has an optical gap of 3.37 eV at 300 K, a resistivity of 10 –4 Ω Cm, and an electronic mobility between 10 and 60 cm 2 s –1 V –1 depending on the microstructure . At the atomic scale, ZnO can crystallize in three different forms: cubic (rocksalt), face-centered cubic (blende), and compact hexagonal (wurtzite).…”