TY - JOUR
T1 - Light-driven urea oxidation for a wearable artificial kidney
AU - Vollenbroek, Jeroen C.
AU - Rodriguez, Ainoa Paradelo
AU - Mei, Bastian T.
AU - Mul, Guido
AU - Verhaar, Marianne C.
AU - Odijk, Mathieu
AU - Gerritsen, Karin G.F.
N1 - Funding Information:
All authors acknowledge the financial support of the strategic alliance of the University of Twente, University Medical Center Utrecht and Utrecht University. The authors would like to thank and acknowledge Gerard Kip for his help in performing the XPS experiments and data processing, Harry Bakker and Karin van Nieuwenhuijzen for their help in performing XRD experiments and data processing, and Johan Bomer for his help in taking SEM images. Erna Fränzel-Luiten and Kim Zijderveld are acknowledged for their support with the ion chromatography experiments.
Publisher Copyright:
© 2023 The Authors
PY - 2023/7/1
Y1 - 2023/7/1
N2 - For the development of a wearable artificial kidney (WAK) that uses a small dialysate volume that is continuously regenerated, it is essential that urea, one of the main uremic retention solutes, is removed. Despite advances in sorbent technology or electro-oxidation no safe, efficient and selective method for urea removal has been reported that allows miniaturization of the artificial kidney to wearable proportions. Here we have developed a flow cell for light-driven, photo-electrocatalytic (PEC) urea removal for use in a WAK. We use a photo-active material (hematite) coated with a catalyst (NiOOH) as working electrode for selective urea oxidation and a silver-chloride (AgCl) cathode. The use of the AgCl counter electrodes eliminates the need for an external bias voltage, and allows operation under light illumination only. Using LED illumination (460 nm) we show that urea is selectively oxidized over chloride. N2 formation is confirmed by gas-phase analysis of the headspace of the sample vial, using mass spectrometry. Other nitrogen containing products include nitrite but importantly ammonia and nitrate are not detected. Using the PEC concept a urea removal rate of 2.5 μmol/cm2h (or 0.15 mg/cm2h) has been achieved. Extrapolating our results to an upscaled system, a surface area of 0.5 m2 would enable efficient removal of the daily produced amount of urea (∼300 mmol) urea within 24 h, when driven by LED illumination only.
AB - For the development of a wearable artificial kidney (WAK) that uses a small dialysate volume that is continuously regenerated, it is essential that urea, one of the main uremic retention solutes, is removed. Despite advances in sorbent technology or electro-oxidation no safe, efficient and selective method for urea removal has been reported that allows miniaturization of the artificial kidney to wearable proportions. Here we have developed a flow cell for light-driven, photo-electrocatalytic (PEC) urea removal for use in a WAK. We use a photo-active material (hematite) coated with a catalyst (NiOOH) as working electrode for selective urea oxidation and a silver-chloride (AgCl) cathode. The use of the AgCl counter electrodes eliminates the need for an external bias voltage, and allows operation under light illumination only. Using LED illumination (460 nm) we show that urea is selectively oxidized over chloride. N2 formation is confirmed by gas-phase analysis of the headspace of the sample vial, using mass spectrometry. Other nitrogen containing products include nitrite but importantly ammonia and nitrate are not detected. Using the PEC concept a urea removal rate of 2.5 μmol/cm2h (or 0.15 mg/cm2h) has been achieved. Extrapolating our results to an upscaled system, a surface area of 0.5 m2 would enable efficient removal of the daily produced amount of urea (∼300 mmol) urea within 24 h, when driven by LED illumination only.
KW - Photo-electrocatalysis
KW - Selective urea oxidation
KW - Wearable artificial kidney
UR - http://www.scopus.com/inward/record.url?scp=85154072862&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2023.114163
DO - 10.1016/j.cattod.2023.114163
M3 - Article
AN - SCOPUS:85154072862
SN - 0920-5861
VL - 419
JO - CATALYSIS TODAY
JF - CATALYSIS TODAY
M1 - 114163
ER -