Solarfuels · Engineering Silicon Carbide Nanowires for Solar Fuels Production

Engineering Silicon Carbide Nanowires for Solar Fuels Production

• What is the problem/issue being addressed? By 2020, the European Union (EU) aims to reduce greenhouse gas emissions by 20-30% and increase renewable energy share to 20%. This scenario has imposed urgent needs to develop fossil fuel alternatives like solar fuels. To produce solar fuels, the coupled reduction of CO2 and H2O is one of the most promising processes. However, the generation of efficient, stable and low-cost material for CO2/H2O reduction remains a big challenge. Silicon carbide nanowires (SiC NW) exhibit the unique properties of large surface-to-volume ratio, tuneable transport properties and quantum size effects, which is very promising for the reduction of CO2/H2O to produce solar fuels. To date, the studies on SiC NW for CO2/H2O reduction are limited due to the lack of (1) large-scale production techniques, (2) in situ characterization of the growth mode, and (3) there are no economical devices available for the evaluation of SiC NW. (Figure 1) This project aims to address these challenges by developing method for large-scale synthesis of SiC NW, studying its growth mechanism via in situ mass spectrometry and building SiC NW-based solar fuel device. • Why is it important for society? The addressing of the above issues allows the production of SiC nanowires in large scale and generation of solar fuels in an efficient and low-cost way. This makes a step closer to meet the targets on the reduction of CO2 emission and the increase of renewable energy share in the EU and worldwide, and to ultimately achieve a low-carbon economy and a sustainable society. • What are the overall objectives? The overall objectives are to develop SiC nanowires for solar fuels production including: 1) To synthesise aligned SiC nanowires in large scale; 2) To study the morphology and growth mechanism of SiC using in-situ characterisation techniques; 3) To evaluate aligned SiC nanowires as photocatalysts. • Conclusions of the action 1) Vertically-aligned SiC nanowires can be synthesised in gram scale from the developed carbon nanotube template method; 2) The diameter and length of SiC nanowires are tuneable by controlling the structure of carbon nanotubes; 3) The growth mechanism of SiC nanowires was revealed by using in-situ mass spectrometry; 4) Photocatalytic evaluation showed that the developed SiC nanowires are photocatalytically-active under visible light; 5) The estimation of band structure for SiC nanowires indicated they are promising for the visible-light-driven photocatalytic reduction of CO2 to produce solar fuels.

Data: CORDIS, © European Union