School of Civil and Environmental Engineering

Ph.D. Thesis Defense Announcement

Synthesis of Two-Dimensional Nanomaterials for Contaminant Removal, Resource Recovery, and Ion-selective Monitoring 

by 

Moyosore Afolabi 

Advisor(s): 

Dr. Yongsheng Chen (CEE) 

Committee Members: 

Dr. Sotira Yiacoumi (CEE), Dr. Xing Xie (CEE), Dr. Katherine Graham(CEE), Dr. Zhaohui Tong (ChBE), Dr. Dequan Xiao (University of New Haven) 

Date &Time: Monday, December 4th, 2023, 9:00 AM - 11:00 AM 

Location: DEEL 303, MS teams 

   To address the escalating demands of a rising global population gravitating toward urban centers, the imperative for sustainable practices in managing food, water, and energy is evident. Wastewater bears both emerging micropollutants (EMPs) such as pharmaceuticals with unknown health risks, also harbors resources crucial for sustainable agriculture (nitrogen, phosphorus, etc.)  and manufacturing (lithium). Leveraging the potential of two-dimensional nanomaterials becomes instrumental in purifying water and selectively sensing lithium ion, and extracting resources from various municipal and industrial wastewater and brines. 
 
   In this thesis, Graphene oxide (GO) and titanium carbide MXenes (Ti3C2Tx) are synthesized and tuned to address environmental challenges, specially focusing on  emerging pollutant removal, nutrient salt resource recovery, and real-time lithium-ion monitoring in water. 
In the first part of our work, the impact of MXene synthesis conditions on surface chemistry and adsorption on antibiotics on MXene membranes is investigated. Through systematic material characterization, adsorption experiments, and density functional theory (DFT) calculations, favorable surface chemistry and synthesis conditions were identified for adsorption of antibiotics. 
   In the subsequent phase of our work, GO membranes were modified with hydrophilic cellulose nanocrystals (CNC) to enable the hybrid membrane. This modification enhances water permeability, antibiotics rejection, and high nutrient salt recovery. 
   The final section of this thesis focuses on lithium ion-selective electrodes (ISE) sensors for precise lithium quantification in wastewater. A MXene-SO3H coating is applied to the Li+ sensor, resulting in heightened sensitivity, rapid response time, and prolonged durability when deployed in wastewater and brine environments. This comprehensive research contributes valuable insights and practical solutions to the pressing challenges associated with the sustainable management of water resources and the mitigation of environmental pollutants.