(351g) Artificial Leaf for Carbon Dioxide Photo-Reduction to Fuels

An artificial leaf that mimics photosynthesis process is a promising approach to directly convert solar energy into energy-rich chemicals^1–4. Thus far, this concept has been successfully developed for the hydrogen generation process^2–4. Here, we have developed an artificial leaf for the conversion of carbon dioxide (CO₂) into synthesis gas in an acidic electrolyte using the energy from a sun simulator. A configuration of the artificial leaf was achieved by using cobalt, as an oxygen-evolving catalyst and molybdenum disulfide (MoS₂) catalyst for CO₂ reduction reaction deposited on the illuminating and back-substrate surfaces of a photovoltaic cell, respectively. We have performed detail experimental studies such as linear sweep voltammetry (LSV) and chronoamperometry (CA), in-situ differential electrochemical mass spectroscopy (DEMS), and gas chromatography (GC) followed by some characterization techniques e.g. scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) to elucidate the performance and stability of our developed artificial leaf. The experimental analyses indicate that our custom made artificial leaf cell can directly convert the solar energy to synthesis gas with a catalytic conversion efficiency of 75%. Our results reveal that the operation of the artificial leaf cell is not restricted by the CO₂ reduction reaction according to the remarkable activity of MoS₂ NFs catalysts⁵. However, it is rather limited by the oxygen evolution reaction (water splitting) at the anode side. This finding could potentially open a new route in the solar-driven CO₂ conversion field where the CO_2 reduction reaction is known to be the bottle neck of this process.

References:

1. Asadi, M. et al. Nanostructured transition metal dichalcogenide electrocatalysts for CO₂ reduction in ionic liquid. Science. 353,467–470 (2016).

2. Kanan, M. W. & Nocera, D. G. In Situ Formation of an Water Containing Phosphate and Co²⁺. Science. 321,1072 (2008).

3. Reece, S. Y. et al. Wireless Solar Water Splitting Using Silicon-Based Semiconductors and Earth-Abundant Catalysts. Science. 334,645–648 (2011).

4. Qiu, F. et al. Photocatalytic Hydrogen Generation by CdSe/CdS Nanoparticles. Nano Lett. 16,5347–5352 (2016).

5. Abbasi, P. et al. Tailoring the Edge Structure of Molybdenum Disulfide toward Electrocatalytic Reduction of Carbon Dioxide. ACS Nano. 11, 453–460 (2017).