CaltechAUTHORS
  A Caltech Library Service

Multilayer Heterojunction Anodes for Saline Wastewater Treatment: Design Strategies and Reactive Species Generation Mechanisms

Yang, Yang and Shin, Jieun and Jasper, Justin T. and Hoffmann, Michael R. (2016) Multilayer Heterojunction Anodes for Saline Wastewater Treatment: Design Strategies and Reactive Species Generation Mechanisms. Environmental Science and Technology, 50 (16). pp. 8780-8787. ISSN 0013-936X. https://resolver.caltech.edu/CaltechAUTHORS:20160801-103401044

[img] PDF (SEM, LSV, and ECSA measurement of anodes, model simulation results, time profiles of ions, the calculation of FC contribution to pollutant removal and energy consumption in wastewater electrolysis. Tables include human wastewater composition and ...) - Supplemental Material
See Usage Policy.

655Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20160801-103401044

Abstract

Multilayer heterojunction SbSn/CoTi/Ir anodes, which consist of Ir_(0.7)Ta_(0.3)O_2 bottom layers coated onto a titanium base, Co-TiO_2 interlayers, and overcoated discrete Sb-SnO_2 islands, were prepared by spray pyrolysis. The Ir_(0.7)Ta_(0.3)O_2 bottom layer serves as an Ohmic contact to facilitate electron transfer from semiconductor layers to the Ti base. The Co-TiO_2 interlayer and overcoated Sb-SnO_2 islands enhance the evolution of reactive chlorine. The surficial Sb-SnO_2 islands also serve as the reactive sites for free radical generation. Experiments coupled with computational kinetic simulations show that while ·OH and Cl· are initially produced on the SbSn/CoTi/Ir anode surface, the dominant radical formed in solution is the dichlorine radical anion, Cl_2·–. The steady-state concentration of reactive radicals is 10 orders of magnitude lower than that of reactive chlorine. The SbSn/CoTi/Ir anode was applied to electrochemically treat human wastewater. These test results show that COD and NH_4^+ can be removed after 2 h of electrolysis with minimal energy consumption (370 kWh/kg COD and 383 kWh/kg NH_4^+). Although free radical species contribute to COD removal, anodes designed to enhance reactive chlorine production are more effective than those designed to enhance free radical production.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/acs.est.6b00688DOIArticle
http://pubs.acs.org/doi/suppl/10.1021/acs.est.6b00688PublisherSupporting Information
http://dx.doi.org/10.1021/acs.est.7b01310DOICorrection
ORCID:
AuthorORCID
Yang, Yang0000-0003-3767-8029
Jasper, Justin T.0000-0002-2461-5283
Hoffmann, Michael R.0000-0001-6495-1946
Additional Information:© 2016 American Chemical Society. Received: February 9, 2016; Revised: June 3, 2016; Accepted: July 12, 2016; Publication Date (Web): July 12, 2016. The authors gratefully acknowledge the financial support of Bill and Melinda Gates Foundation (BMGF-RTTC Grant, OPP1111246). The authors declare no competing financial interest.
Funders:
Funding AgencyGrant Number
Bill and Melinda Gates FoundationOPP1111246
Issue or Number:16
Record Number:CaltechAUTHORS:20160801-103401044
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20160801-103401044
Official Citation:Multilayer Heterojunction Anodes for Saline Wastewater Treatment: Design Strategies and Reactive Species Generation Mechanisms Yang Yang, Jieun Shin, Justin T. Jasper, and Michael R. Hoffmann Environmental Science & Technology 2016 50 (16), 8780-8787 DOI: 10.1021/acs.est.6b00688
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:69347
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:01 Aug 2016 18:05
Last Modified:14 Apr 2020 17:30

Repository Staff Only: item control page