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

Abstract

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 TiO 2 in a H 2 atmosphere at different temperatures, the Magneĺi 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 V OC value was increased by ∼5 times and I SC 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 V OC output of ∼600 mV, combined with the surface hydrophobic treatment technology.

Enhanced Electricity Generation from Graphene Microfluidic Channels for Self-Powered Flexible Sensors

“…As the droplet moves on the graphene, electrons are drawn and released from the graphene under two moving boundaries of the electrical double layer (EDL). The induced voltage is formed in graphene by charge and discharge of pseudocapacitance at the front and rear of droplet, respectively. , In addition to carbon nanomaterials being used to develop hydrovoltaic generators, various materials are introduced to improve performance and to investigate its electricity generation mechanism, such as MoS 2 , metal oxide films, Cu x O nanowires, and Ti 4 O 7 . The performance is also enhanced because of the strong negative triboelectric potential of PTFE substrate, which highlights the importance of substrate effect. − Nevertheless, the variation of droplet behavior caused by the device structure is barely considered, which is an inevitable and crucial step in the microscopic power generation process, and its influence on induced voltage cannot be ignored.…”

Mixed-Dimensional van der Waals Heterostructures for Boosting Electricity Generation

“…Conversely, the reduced device resistance leads to an accelerated rate of decrease in the induced voltage because the SiC w mesh underlayer, which is enriched with a large number of water molecules, exhibits conductivity. 54 Because of the weaker shielding effect of the hydroxide cations compared to chloride cations, 6,17 NaOH solution with an equivalent concentration exhibits higher output voltage than NaCl solution (Figure 3f). The observed reverse voltage is attributed to variations in the concentrations of HCl droplets, which is flowing as reported previously.…”

“…Because of the weaker shielding effect of the hydroxide cations compared to chloride cations, , NaOH solution with an equivalent concentration exhibits higher output voltage than NaCl solution (Figure f). The observed reverse voltage is attributed to variations in the concentrations of HCl droplets, which is flowing as reported previously. , The underlayer consisting of chemically stable SiC w building blocks confers the device with the capability of electricity generation in extreme environmental applications.…”

“…The generation of the induced voltage in graphene is attributed to the charge and discharge of pseudocapacitance. Although droplet flow-induced generators are capable of yielding high levels of instantaneous power density with relatively facile device configurations, the energy conversion efficiency of hydrovoltaic generators is still being pursued by exploring different low-dimensional functional materials − and designing distinctive device structures . In addition to the feasibility of substitutional doped graphene to enhance electricity generation, , it has been demonstrated experimentally and theoretically that the graphene substrate is equally significant for regulating the output performance of graphene-based flow-induced generators. − Notably, when mentioning the substrate effect of graphene, it inevitably involves the transfer of graphene onto the target substrate to exploit its properties. , So far, traditional wet transfer is the most widely adopted and straightforward strategy regarding the assembly of generators. ,,,, Despite the progress therein, this transfer procedure is not only tedious but also likely to introduce polymer residues and mechanical/chemical defects, resulting in significant degradation of the device performance. − Because of this, further attempts, such as generators based on directly grown graphene free of transfer-related contaminants, unavoidable damage, and corrugation, exhibited higher induced voltage and excellent long-term durability .…”

Out‐Of‐Plane Electrokinetics via Pumping Potential Achieved by 100 nm‐Thin Polyethylene Nanomembranes

“…Recently the selection principle of DEG's conductors has been concluded as adequate electron conduction within a 2D-confined thickness. [2,16] Although with few alternatives reported, [13,17,[26][27][28][29] this principle severely constrains DEG's study and application scenarios.…”