Presentation Title

Photocatalytic Microreactors for Water Purification

Faculty Mentor

Dr. Masaru Rao

Start Date

17-11-2018 8:30 AM

End Date

17-11-2018 10:30 AM

Location

HARBESON 60

Session

POSTER 1

Type of Presentation

Poster

Subject Area

engineering_computer_science

Abstract

As our interest in deep space travel increases, improvements to the Water Processor Assembly (WPA) on the International Space Station are necessary. Thermal catalytic reactors currently used in the WPA experience wear and tear due to harsh operating conditions. Herein, we propose a photocatalytic microreactor for water purification that operates at ambient pressure and temperature, thereby minimizing the amount of maintenance required. The chamber of the microreactor consists of a micropillar array coated with nanoporous titania (NPT), which catalyzes the degradation of volatile organic compounds under UV light. Compared to planar reactor chambers, the incorporation of pillars increases the catalytic surface area by 3 times and reduces the diffusion pathways of contaminants.

The microreactor is fabricated on a titanium wafer via photolithography, dry etching, and submersion of the etched wafer into hydrogen peroxide to grow NPT. The etched features and NPT surface are characterized via Scanning Electron Microscopy. The wafer is bonded to PMDS and quartz in a 3D-printed fixture set to ensure a leak-tight seal. The catalytic efficiency of the device was determined by measuring the degradation of a known concentration of methylene blue via UV-Visible Spectroscopy. Our findings show that a planar NPT reactor yielded a percent degradation of 45% at 150µL/min and 76% at 50µL/min, which is comparable to other photocatalytic microreactors reported in literature. Our future work involves improving NPT growth on the micropillar array and quantifying the effect of micropillars on performance.

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Nov 17th, 8:30 AM Nov 17th, 10:30 AM

Photocatalytic Microreactors for Water Purification

HARBESON 60

As our interest in deep space travel increases, improvements to the Water Processor Assembly (WPA) on the International Space Station are necessary. Thermal catalytic reactors currently used in the WPA experience wear and tear due to harsh operating conditions. Herein, we propose a photocatalytic microreactor for water purification that operates at ambient pressure and temperature, thereby minimizing the amount of maintenance required. The chamber of the microreactor consists of a micropillar array coated with nanoporous titania (NPT), which catalyzes the degradation of volatile organic compounds under UV light. Compared to planar reactor chambers, the incorporation of pillars increases the catalytic surface area by 3 times and reduces the diffusion pathways of contaminants.

The microreactor is fabricated on a titanium wafer via photolithography, dry etching, and submersion of the etched wafer into hydrogen peroxide to grow NPT. The etched features and NPT surface are characterized via Scanning Electron Microscopy. The wafer is bonded to PMDS and quartz in a 3D-printed fixture set to ensure a leak-tight seal. The catalytic efficiency of the device was determined by measuring the degradation of a known concentration of methylene blue via UV-Visible Spectroscopy. Our findings show that a planar NPT reactor yielded a percent degradation of 45% at 150µL/min and 76% at 50µL/min, which is comparable to other photocatalytic microreactors reported in literature. Our future work involves improving NPT growth on the micropillar array and quantifying the effect of micropillars on performance.