Generation of fuel from CO2 saturated liquids using a p-Si nanowire ‖ n-TiO2 nanotube array photoelectrochemical cell

Abstract

Light-driven, electrically biased pn junction photoelectrochemical (PEC) cells immersed in an electrolyte of CO(2) saturated 1.0 M NaHCO(3) are investigated for use in generating hydrocarbon fuels. The PEC photocathode is comprised of p-type Si nanowire arrays, with and without copper sensitization, while the photoanode is comprised of n-type TiO(2) nanotube array films. Under band gap illumination, the PEC cells convert CO(2) into hydrocarbon fuels, such as methane, along with carbon monoxide and substantial rates of hydrogen generation due to water photoelectrolysis. In addition to traces of C3-C4 hydrocarbons, methane and ethylene were formed at the combined rate of 201.5 nM/cm(2)-hr at an applied potential of -1.5 V vs. Ag/AgCl. The described technique provides a unique approach, utilizing earth abundant materials, for the photocatalytic reduction of CO(2) with subsequent generation of higher order hydrocarbons and syngas constituents of carbon monoxide and hydrogen.

Synthesis and characterization of iron-doped titania nanohoneycomb and nanoporous semiconductors by electrochemical anodizing method as good visible light active photocatalysts

“…These characteristics make them suitable candidates in various technologies such as solar cells, removal of pollutants, water splitting, sensors, drug delivery, CO 2 conversion and so on. Currently, research into new nanostructures derived from TiO 2 -based materials holds great promise to help address many urgent global challenges [38][39][40][41][42][43][44].…”

Achievements and Trends in Photoelectrocatalysis: from Environmental to Energy Applications

“…Nowadays, photoelectrocatalysis is a technique with consolidated principles that has gained prominence and has been successfully applied in organic compound oxidation [4][5][6], inorganic ion reduction [7,8], microorganism inactivation [9,10], CO 2 reduction [11,12], and production of electricity and hydrogen [13][14][15][16]. The subject has since been explored by several researchers and reviews of deserving notoriety [13,[17][18][19][20].…”

Recent progress on advanced design for photoelectrochemical reduction of CO2 to fuels

“…A pioneering work was the PEC cell reported by Grimes et al [30] using p-Si nanowires and n-TiO 2 nanotube arrays as electrodes. Although hydrogen evolution was still predominant, this setup obtained CO as the main product of CO 2 reduction under light illumination with a production rate of 824 nmol L −1 h −1 cm −2 at −1.5 V versus Ag/AgCl.…”

“…1a). Numerous p-type semiconductors have been exploited and investigated, including silicon [29,30], metal oxides [31][32][33], sulfides [34,35], tellurides [36,37], phosphides [38,39] and others [40,41]. In addition, profiting from the remarkable activity for CO 2 adsorption and activation, metal materials (e.g., Pd, Au, Ag and Cu) usually serve as the cathodes in electrochemical CO 2 reduction [42].…”