Gradient Doped Polymer Nanowire For Moistelectric Nanogenerator

The increasingly severe environmental and energy-related issues impel people to pay attention to designing and fabricating renewable energy related materials and devices.It is extremely important for searching simple and efficient renewable energyto achieve sustainable energy and social development.However,a great deal of potential energy in nature can notbe converted into available electric power,due to lack of new energy-conversion technology.Recently,an advanced energy-conversion technology called moisture-electric energy tranformation has been developed,which can harvest energy from ambient moisture diffusion.Nevertheless,an obvious limit of previous work is thatdue to the poor interaction between moisture and block materials,the output power of the moistelectric nanogenerator is quite low,which greatly restricts its practical application.In this work,we report a high performance moisture-activated nanogenerator based on one-dimensional(1D)conductive polymer nan owire with a preformed sulfonate iongradient.The low-dimensional nanomaterials can response to trace moisture and facilitate the diffusion of water molecules or other carriers,which offer a promising opportunity to realize environmental energy harvesting.The main research and results are as follows:In the first part,we developed a concentration-controlled electro-deposition(CCED)technique for fabrication of sodium ion gradient doped polypyrrole nanowire(GDNw)in sodium dodecyl benzene sulfonate(SDBS)solution.The apparent gradient distribution and unique 1D nanostructure favor efficient ion transfer,water molecules harvesting and diffusion.As a result,the as-prepared single GDNw exhibited a high-output voltage of 75m V and a remarkable output power of 103.13 m W?cm^-2.More interestingly,the 1D moistelectric nanogenerator exhibited highly asymmetrical alternating electric output and self-rectification properties which may be a promising route for serving as pulsing direct current energy sources in nanodevices(e.g.,nanobots).The later research was based on the first pary,by vertically integrating numerous GDNw into arrays(GDNa),it shows a significant improvement in current output,a slight moisture stimulation can generate 140 n A output current without voltage drop.The GDNw nanogenerator can also be designed into array integrated patterns(GDNa),thereby obtaining the sharp increasing of current output and power just like numerous parallel connecting nano-batteries.The ordered array made up with individual nanowire not only shows the individual characters,but also has greatly increased the current/power output,and meet the requirements of macro generator devices.We believe that the promising moistelectric nanogenerators developed here will have great applications in self-powered devices and sensing systems.