High speed manufacturing of laser-textured surfaces for visible-light plasmon-enhanced CO2 conversion

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Our reliance on fossil fuels and impact on the climate is not sustainable and requires immediate action. My research program proposes to tackle these issues by catalyzing the CO2 reduction reaction on laser-textured surfaces for the production of useful fuels and to decrease CO2 emissions. The research proposal consists of four interconnected parts: i) We first propose to use laser surface texturing to control both micro- and nano-scale morphology and chemistry on the surface of copper and silver. Parameters such as laser wavelength, repetition rate, and pulse length, as well as machining environment will be optimized for the photocatalytic reduction of CO2 via visible light activated surface plasmons. Surface plasmons are collective oscillations of electrons that result in enhanced light absorption on nanostructures that can catalyze chemical reactions. ii) A suite of state-of-the-art techniques will be used to characterize the surface morphology, chemistry and surface plasmon resonance, and their evolution over time. Techniques such as Raman microscopy, x-ray photoelectron spectroscopy (XPS), fourier-transform infrared spectroscopy (FTIR), spectrophotometry, and electron and atomic force microscopy will paint a complete picture of the surface morphology and chemistry. iii) Once the surface texture is fully characterized, the reduction of CO2 via visible-light activated surface plasmons will be evaluated. We will concentrate on the electrocatalytic CO2 reduction reaction using laser nanotextured copper and silver as the catalysts. Copper and silver are efficient catalysts and have strong visible-region localized surface plasmon resonances that can lower reaction barriers and drive chemical reactions. Catalytic efficiency and selectivity will be assessed using an electrocatalytic cell coupled with a mass spectrometer, and liquid and gas chromatographs under artificial sun illumination. iv) While ultrafast lasers could texture large surfaces in a reasonable time, high speed manufacturing techniques such as stamping and cold rolling would be much more time and cost effective. Stamping and cold rolling will therefore be used to transfer laser micro and nanoscale textures from die to parts. Catalytic properties, die life-time, and resilience of micro and nanoscale features will be investigated. The combination of laser micromachining and high-speed transfer processes for CO2 conversion has never been done, and promises to contribute to mitigate global warming and the dangerous effects of climate change while at the same time providing a green source of fuels. In addition to new scientific discoveries, industrial applications, and environmental benefits, the proposed research program will provide training to students on state-of-the art equipment, methodologies, and problem-solving skills in the areas of laser surface texturing, surface characterization, high speed manufacturing, and solar plasmon-enhanced photochemistry.