Tunable Silver Modified Engelhard Titanosilicate Core-Shell Heterostructure for Visible Light Photocatalysis

Emily T. Buttafuoco, Mariam N. Ismail Chemistry and Physics Department Simmons University, Boston, MA 02115

The EPA estimates that the United States releases over 850 billion gallons of untreated wastewater into the environment annually. One method to remove these toxic and hazardous pollutants from the environment is semiconductor photocatalysis, which is the process of photocatalytic degradation via light absorption to oxidize or reduce the pollutants into nontoxic forms. Engelhard Titanosilicate (ETS-10) is a common zeo-type material containing well-defined semiconductor monoatomic … Ti-O-Ti-O-Ti… chains. These chains result in ETS-10 having a bandgap energy of 4.03 eV, creating a promising candidate for photocatalytic applications under ultraviolet light irradiation. To overcome the broad bandgap of ETS-10 for use in visible light photocatalysis, modification using silver (Ag) nanoparticles (NPs) has been explored for its surface plasmon resonance (SPR) abilities that extend the photocatalytic ability to visible light. The SPR wavelength exhibited under visible light and the size of the Ag NPs can be tuned using various synthesis techniques. Preliminary experiments revealed that the exposed Ag NPs on the surface of ETS-10 react with the surrounding medium, resulting in the dislodgement of the NPs and further contamination of the system. Core-shell silver modified ETS-10 was synthesized in order to protect the Ag nanoparticles while allowing the photocatalytic enhancement. Titanosilicate ETS-10 was synthesized via hydrothermal synthesis from an optimized system with a molar composition of 5.2Na2O:0.5K2O:1.0TiO2:5.5SiO2:113H2O at pH 10.6-10.7 for 2-4 days at 503K. Ag-modified-ETS-10 crystals were prepared via photodeposition, photoreduction, and chemical reduction techniques in order to explore the effect of tuning the size of Ag NPs on the SPR wavelength. Variables such as temperature, silver nitrate concentration, and irradiation time are currently under investigation. The core-shell heterostructure was synthesized via secondary growth to form a layer of ETS-10 over the Ag-ETS-10. Photocatalysis experiments with methylene blue will be conducted to test the effectiveness and reusability of the heterostructure system.

Additional Abstract Information

Presenter: Emily Buttafuoco

Institution: Simmons College

Type: Poster

Subject: Chemistry

Status: Approved

Time and Location

Session: Poster 4
Date/Time: Tue 11:00am-12:00pm
Session Number: 3530