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CURATOR
A pinboard by
Xin Ying Kong

PhD Student, Monash University Malaysia

PINBOARD SUMMARY

My research mainly focuses on photocatalytic CO2 reduction into energy-rich hydrocarbon fuels.

Over the past few decades, blooming of human population and increase of life quality have led to large-scale burning of fossil fuels to meet the global energy demand. As a result, the non-renewable energy source is experiencing rapid depletion, along with massive CO2 greenhouse gas emissions to the atmosphere. In the light of this, incessant research efforts have been devoted to addressing these global energy and environmental issues. Among all the existing approaches, photocatalytic CO2 reduction is deemed as the most sustainable and promising avenue as these notorious CO2 molecules can be transformed back into energy-rich hydrocarbon fuels with solar light as the only energy input. Thus, this process is reputed as reverse combustion or artificial photosynthesis. Nonetheless, the state-of-the-art advances is still far from being industrialized as most of the existing photocatalysts are only responsive to UV and/or visible light, which constitute for only <5% and ~45% of solar spectrum, respectively. The harnessing of near-infrared (NIR) region (~50% of solar light), is highly desirable but challenging owing to its low-photonic energy.

Very recently, I have successfully realized photocatalytic CO2 reduction over full spectrum – from UV to NIR region through surface defect engineering of bismuth tungstate (Bi2WO6). This was incredibly achieved without involving any expensive noble metals or co-catalysts. As far as I know, this is the first research work in Malaysia which demonstrated NIR-driven CO2 reduction, and also the first study in the world that reports on CO2 reduction over UV-Vis-NIR light. Following my first success, I have further developed CQDs-decorated ultrathin Bi2WO6 nanosheets for enhanced photocatalytic performance. My current research focuses on designing novel advanced nanomaterials through strategic coupling, crystal facet engineering and surface defect engineering for achieving superior CO2 reduction photoactivity, with an aim of alleviating environmental issues and imminent energy crisis concurrently.

9 ITEMS PINNED

Facet- and structure-dependent catalytic activity of cuprous oxide/polypyrrole particles towards the efficient reduction of carbon dioxide to methanol.

Abstract: The preparation of cost-effective, stable catalysts for the selective reduction of carbon dioxide (CO2) to C1 products such as methanol is extremely important because methanol can be used directly as a fuel or it can be converted into other value-added products. However, the catalysts currently used for the reduction of CO2 to methanol exhibit poor selectivity, poor stability and very low faradaic efficiency. Herein, we used low-cost, stable cuprous oxide/polypyrrole (Cu2O/Ppy) particles having structures of octahedra and icosahedra (microflowers) that were prepared on linen texture (LT) papers for the selective reduction of CO2 to form a value-added single C1 product, methanol. The Cu2O/Ppy particles possessing both octahedral and microflower shapes with exposed low-index (111) facets and high-index (311) and (211) facets are denoted as Cu2O(OL-MH)/Ppy particles. The as-prepared Cu2O(OL-MH)/Ppy particles exhibited high catalytic activity and selectivity towards the electrochemical reduction of CO2 at -0.85 V vs. RHE to form methanol, with a faradaic efficiency of 93 ± 1.2% and an average methanol formation rate of 1.61 ± 0.02 μmol m-2 s-1. The X-ray photoelectron spectroscopy (XPS) analysis revealed that the pyrrolic nitrogen atoms present in the Ppy shell played a dominant role as active sites for CO2 molecules. The Raman bands of Ppy and Cu2O did not shift even after being subjected to electrolysis for several hours, suggesting superior stability of the Cu2O(OL-MH)/Ppy particles. The high resolution microscopic, spectroscopic, diffraction and electrochemical analysis results clearly revealed that the Ppy shell protected the Cu2O particles and avoided corrosion, dissolution, and structural and crystal facet changes, leading to greater stability. The low-cost, durable, flexible, and catalytically active Cu2O(OL-MH)/Ppy LT paper holds great potential for catalytic, photocatalytic and energy storage applications.

Pub.: 14 Jun '18, Pinned: 30 Jun '18