| AVS 64th International Symposium & Exhibition | |
| Biomaterial Interfaces Division | Wednesday Sessions |
| Session BI+NS-WeM |
| Session: | Biomaterials and Nanomaterials Fabrication & In Honor of Dave Castner's 65th Birthday: Multitechnique Bio-Surface Characterization I |
| Presenter: | Stefan Zauscher, Duke University |
| Authors: | K.E. Marusak, Duke University Y. Feng, Duke University E. Ngaboyamahina, Duke University Y. Cao, Duke University J.T. Glass, Duke University L. You, Duke University S. Zauscher, Duke University |
| Correspondent: | Click to Email |
We present a new method for the fabrication of semiconducting, transition metal nanoparticles (NPs) with tunable bandgap and useful photoelectric properties, through bacterial precipitation. Escherichia coli bacteria have been genetically engineered, by overexpression of a cysteine desulfhydrase gene, to precipitate transition metal NPs from solution, here more specifically, cadmium sulfide (CdS). Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) revealed that the bacterially precipitated NPs are agglomerates of mostly quantum dots (QDs), with a diameter of 4-5 nm, in a carbon-rich matrix. We discovered that the precipitation conditions of the bacteria can be tuned to produce NPs with bandgaps that range from quantum-confined to bulk CdS. Furthermore, we determined their photoelectrochemical (PEC) properties and their energy band structure by electrochemical measurements. In addition, by taking advantage of the organic matrix, which is residual from the biosynthesis process, we fabricated a prototype photocharged capacitor electrode by incorporating the bacterially precipitated CdS with a reduced graphene oxide (RGO) sheet. Our results show that bacterially precipitated CdS NPs are potentially useful components for PEC devices with applications for energy conversion and storage.
References:
1) Katherine E. Marusak, Yaying Feng, Cooper F. Eben, Stephen T. Payne, Yangxiaolu Cao, Lingchong You, Zauscher, S. “Cadmium sulphide quantum dots with tunable electronic properties by bacterial precipitation,” RSC Advances, 2016,6, 76158-76166.
2) Yaying Feng, Edgard Ngaboyamahina, Katherine E. Marusak, Yangxiaolu Cao, Lingchong You, Jeffrey T. Glass, and Stefan Zauscher, "Hybrid (Organic/Inorganic) Electrodes from Bacterially Precipitated CdS for PEC/Storage Applications," The Journal of Physical Chemistry C 2017121 (7), 3734-3743