Efficient Photocatalytic Bismuth Composite Nanofiber with in Situ Temperature Sensor

Description

The development of human society is hindered by environmental pollution and energy crisis, and these problems need to be addressed. Photocatalysis, the use of light to accelerate a chemical reaction, has received much attention recently because it can utilize effectively clean and renewable solar energy, converting the energy directly into chemical energy to decompose organic pollutants. The process is energy saving, relatively cheap, environmentally friendly, sustainable, and has a wide range of applications, from water treatment, deodorization, dirt prevention, to energy conversion. The chemical reaction is temperature dependent and in situ temperature monitoring of the catalytic process is desirable, however, at this time there is no effective way to do this. Hence, further investigation and development of the process is required, and it is an important strategic plan in many countries. Different from traditional mainstream catalysts such as titanium dioxide and zinc oxide, bismuth-based oxide semiconductor is unique and plays an important role in the photocatalytic process. The oxide semiconductor has wide band gap change, high refractive index, good photoconductivity and photoluminescence, and is attractive due to its non-toxic, low-cost, narrow band gap, thermally stable, high corrosion resistance, excellent electron mobility, and high visible light induced photocatalytic activity. However, the semiconductor suffers from small specific surface area, insufficient active site, low charge carrier’s separation, powder agglomeration, and low efficiency. These drawbacks must be overcome to enable practical and commercial application of this material. To overcome the above-mentioned shortcomings, dual function photocatalytic core-shell structured composite nanofibers will be investigated in this project. The fiber core is comprised of rare earth ions doped low phonon energy oxysulfide material in polymethyl methacrylate for in situ temperature monitoring. The introduction of rare earth ions will also enhance further the photocatalysis process through upconversion luminescence, and optical thermometry for temperature sensing based on monitoring the variation in fluorescence intensity can be realized using the lanthanide doped material. The fiber shell is comprised of bismuth-based oxide semiconductor with graphite carbon nitride in polyacrylonitrile. The addition of carbon nitride will provide additional active site and promote further spatial charge separation, leading to enhanced photocatalytic activity and efficiency. To avoid the powder agglomeration issue, the composite nanofibers will be fabricated using a modified, controllable, and cost-effective coaxial electrospinning process. The novel composite nanofibers are expected to have wide photocatalytic response range, large adsorption capacity, good temperature control performance, and will provide new reference in the development of photocatalytic technology and application.