基于新型量子点光电化学酶生物燃料电池的研究

Photoelectrochemical enzymatic biofuel cell (PEBFC) shows the obvious advantages in the renewable energy conversion field, tailoring sunlight harnessing components to the cell to achieve dual-directional energy conversion. However, the performance of the PEBFC can not satisfy the demand of the practical application. The main reason is that the utilization efficiency of solar energy by PEBFC is rather low. Meanwhile, the slow electron transfer between the catalytic center of enzymes and electrode hampers the power output of the PEBFC. According to the current situation, we will focus on the development of the novel quantum dots, and try to utilize visible solar light as the excitation power source. We will also develop the novel functionalized nanomaterials for the link of enzymes, improve the stability of the photocatalyst and biomoleculars, and extend the lifetime of the device. The major investigations are as follows: (1) Design and synthesize the novel quantum dots, which can generate the electron and hole under the visible light, and improve the utilization efficiency of the photocatalyst for solar energy; (2) Fabricate the functionalized nano-carbon materials, and with the special spatial structure and functional group, the carbon materials can raise the loading of the enzymes, accelerate the electron transfer rate between the catalytic center of the enzymes and the underlying electrode, and stabilize the senior structure of the enzymes; (3) Ingeniously design the structure of the PEBFC, improve the performance of the PEBFC greatly, and realize the practice application of the device.

光电化学酶生物燃料电池在可再生能源转化方面显示出独特的优势，该类电池将太阳能引入酶生物燃料电池，可以实现二元能量转化。但该类电池性能还远达不到实际应用的要求。目前最主要原因是器件对太阳光的利用效率太低。酶和电极之间的缓慢电子传递也是制约电池功率输出的瓶颈。综合当前的研究现状，本项目的重点为开发新型量子点材料，充分利用可见光作为光源，同时开发固定酶的新型功能化纳米材料，提高光催化剂和酶的稳定性，延长器件的使用寿命。主要探索方向如下：（1）设计合成在可见光激发下产生光电流和空穴的新型量子点材料，大幅提高光催化剂对太阳光的利用效率。（2）制备特定功能化的新型纳米碳材料，利用其独特的空间结构和功能化基团，大幅提高酶在电极表面的负载量，显著加快酶的催化中心和电极表面的电子传递速率，明显增强酶高级结构的稳定性。（3）巧妙设计电池构造，大幅提高电池性能，实现电池的实际应用。

光电化学酶生物燃料电池在可再生能源转化方面显示出独特的优势，该类电池将太阳能引入酶生物燃料电池，可以实现二元能量转化。本项目的重点为开发新型量子点材料，并成功开发了基于graphene-CdS、graphene-CuInS2、graphene-CdSe、CdSeTe和graphene quantum dots(QDs)等新型半导体发光材料，其可以在可见光激发下实现有效的光电子和空穴分离。将graphene-CdS量子点纳米复合材料修饰的TiO2纳米棒阵列作为光电阳极，可以在可见光激发下氧化抗坏血酸产生光电流。同时将漆酶化学键合在3D graphene-SWCNTs内部，构建酶生物燃料电池的生物阴极，在电子媒介体ABTS的作用下，可以成功实现对氧气的还原。基于该类设计的光电化学酶生物燃料电池(PEBFC)的开路电压和最大的功率密度分别为1.05 V和227.5 μW cm-2。当串联两个PEBFC结构单元时，其开路电压可达2.05 V,可以顺利点亮额定电压为1.8 V的红色LED。该类PEBFC开创了多渠道能源同时转化的方法，发展了能源转化设备的设计理念。因此PEBFC具有广泛的应用前景，可望将来成为一类新型绿色可再生能源。