Origin of Enhanced Electricity Generation on Magnéli Phase Titanium Suboxide Nanocrystal Films

The energy conversion process caused by relative motion of droplets and nanofilms has aroused widespread attention. However, the mechanism is still unclear, especially regarding the modification of the nanomaterial itself. In this study, we found that by annealing TiO2 in a H2 atmosphere at different temperatures, the Magnéli phase titanium suboxide can be prepared with a lot of oxygen vacancies. Oxygen vacancies not only form negative charge centers inside the film, which enhance the attraction of Na+, but also increase the carrier concentration. By increasing the oxygen vacancy concentration, the measured VOC value was increased by ∼5 times and ISC by ∼30 times. Furthermore, a universal film preparation process was developed for the large-scale production of flexible energy conversion units based on the simple sol–gel method. Experimental results show that the prepared energy conversion unit has excellent performance of collecting rainwater energy and show a stable and continuous VOC output of ∼600 mV, combined with the surface hydrophobic treatment technology.