Project Info


Hydrogen Fuel from Sunlight and Water

Tom Furtak | tfurtak@mines.edu

Nature has evolved very effective mechanisms for converting solar energy into useful fuel through photosynthesis in green plants. In this process water and carbon dioxide are combined in a photochemical reaction, aided by organic catalysts, to yield carbohydrates and oxygen. These steps can be duplicated in the laboratory to help understand how photosynthesis works. Armed with that knowledge, scientists have discovered ways to generate, not sugar, but hydrogen, through what has been called solar water splitting. Using only water as the starting material, these methods employ photoelectrochemical action to generate hydrogen and oxygen. There has been intense interest in optimizing these processes with the objective of providing solar-driven fuel production for a hydrogen-based energy economy [1,2]. For example, hydrogen fuel cells would power electric vehicles without adding any carbon to the environment.

A typical embodiment of solar water splitting works as follows: Photons are absorbed in an n-type semiconductor that may be coated with an oxidation catalyst. Photo-excited carriers (electrons) in the semiconductor move into a wire connected to an inert metal (such as platinum). Both materials are immersed in an aqueous electrolyte. Oxygen bubbles are evolved on the semiconductor and hydrogen bubbles are generated on the metal. Among the most promising n-type materials for water splitting is bismuth vanadate (BiVO_4), which we have been working with for several years [3,4]. We have recently fabricated high-quality BiVO_4 thin films using a novel electrochemical method [5].

The objective of this project will be to optimize the electrodeposited BiVO_4 films using surface and bulk modifications[6], and to test these improved materials in solar water splitting experiments. This will involve producing thin films of the semiconductor, operating optical excitation and measurement instrumentation, and handling a photoelectrochemical sample chamber. The project will also include characterization of the materials using x-ray diffraction, electron microscopy, and optical absorption spectroscopy. The ideal outcome would be a body of data that could be published in an article submitted to a scientific journal.

More Information

1. Thalluri, S. M., Bai, L., Lv, C., Huang, Z., Hu, X., and Liu, L. “Strategies for Semiconductor/Electrocatalyst Coupling toward Solar-Driven Water Splitting” Advanced Science 7, no. 6 (2020): 1902102. doi:10.1002/advs.201902102

2. Jiang, C., Moniz, S. J. A., Wang, A., Zhang, T., and Tang, J. “Photoelectrochemical Devices for Solar Water Splitting – Materials and Challenges” Chemical Society Reviews 46, no. 15 (2017): 4645–4660. doi:10.1039/C6CS00306K

3. Pilli, S. K., Furtak, T. E., Brown, L. D., Deutsch, T. G., Turner, J. A., and Herring, A. M. “Cobalt-Phosphate (Co-Pi) Catalyst Modified Mo-Doped BiVO(4) Photoelectrodes for Solar Water Oxidation” Energy & Environmental Science 4, no. 12 (2011): 5028–5034. doi:10.1039/C1EE02444B

4. Pilli, S. K., Janarthanan, R., Deutsch, T. G., Furtak, T. E., Brown, L. D., Turner, J. A., and Herring, A. M. “Efficient Photoelectrochemical Water Oxidation over Cobalt-Phosphate (Co-Pi) Catalyst Modified BiVO4/1D-WO3 Heterojunction Electrodes.” Physical Chemistry Chemical Physics : PCCP 15, no. 35 (2013): 14723–14728. doi:10.1039/c3cp52401a

5. Govindaraju, G. V, Wheeler, G. P., Lee, D., and Choi, K.-S. “Methods for Electrochemical Synthesis and Photoelectrochemical Characterization for Photoelectrodes” Chemistry of Materials 29, no. 1 (2017): 355–370. doi:10.1021/acs.chemmater.6b03469

6. Kim, J. H. and Lee, J. S. “Elaborately Modified BiVO 4 Photoanodes for Solar Water Splitting” Advanced Materials 31, (2019): 1806938. doi:10.1002/adma.201806938

Grand Engineering Challenge: Make solar energy economical

Student Preparation


Qualifications

The student should have completed the basic chemistry sequence (Chem I and Chem II) at Mines. Any additional experience with chemical synthesis and/or electrochemistry is also desirable, but not required.

Time Commitment

25 hours/month

Skills/Techniques Gained

The student will gain an understanding of electrochemical phenomena, photovoltaic and photo-electrochemical processes, optical spectroscopy, x-ray diffraction, electron microscopy, electrochemical instrumentation, small signal processing, data analysis, and data presentation. In addition, the student will learn fundamentals of material synthesis involving electrodeposition, and high-temperature sintering.

Mentoring Plan

The student will meet with Prof. Furtak for one-hour research review sessions every week. In addition, he will personally mentor the student in laboratory methods necessary to complete the project successfully.