Pyrite nanotube array films as an efficient photocatalyst for degradation of methylene blue and phenol

Abstract

Pyrite crystal is used as a potential catalyst for the degradation of pollutants or removing waste gas in environmental engineering. However, the traditional pyrite synthetic process could lead to intermediate phases during formation of pyrite, such as FeS or Fe 1Àx S, hurting the purity of the products. In this study, pure FeS 2 nanotubes with a stoichiometric ratio were fabricated by vulcanizing the precursor nanotubes.The photocatalytic activity of nanotubes was investigated via decomposing methylene blue and phenol.The results indicated that the oxidation of pyrite affected the photocatalytic activity of pyrite nanotubes slightly. Comparing with the pyrite piled microparticle coating and the hematite nanotube coating, the visible light driven catalytic activity of the pyrite nanotube coating was derived from increased production of hydroxyl radicals. The topography of the nanotube array contributed to the generation of the photoinduced hole + and separation of the e À /hole + pairs, eventually enhanced photocatalysis performance. In addition, Fe 2 O 3 nanotubes can decompose MB effectively, however, hardly degrade phenol. This work offers insight to develop transition metal based semiconductor photocatalysts for environmental and energy utilization.

Solvent-less method for efficient photocatalytic α-Fe2O3 nanoparticles using macromolecular polymeric precursors

“…To our knowledge, this approach provides the first evidence of all solid state production of nanoparticle of single crystalline, pure Fe 2 O 3 with highly efficient photocatalytic behavior of pristine nanostructures for degradation of organic pollutants, such as MB. [73][74][75][76][77][78] Ayachi and co-workers 79 have reported hematite Fe 2 O 3 nanoplatelets with a MB photocatalytic degradation of 47% after 4.5 h of irradiation time. To compare the efficiency of our system, we note that many literature reports with better photocatalytic performance using Fe 2 O 3 often use host materials or hetero-nanostructures using oxide with significant UV absorption and electronic conductivities such as Fe 2 O 3 @TiO 2 , systems with B98-100% reported efficiency, or Fe 2 O 3 -TiO 2 using Al, Zn, Cu or a-Fe 2 O 3 /Bi 2 MoO 6 (23-70%) to degrade MB, Rhodamine B, 2,4-dichlorophenoxyacetic acid, malachite green and acid orange 7 at 90-150 min.…”

Electronic Dynamics in Natural Iron Pyrite Studied by Broadband Transient Reflection Spectroscopy

“…4,5 Such properties render pyrite a suspect in the origin of life on earth 6−8 and an extremely intriguing material for application in sustainable energy technologies such as photovoltaics 3,9−12 and photocatalysis. 13,14 In addition to these, more suggested applications of iron pyrite continue to come forth, including broadband photodiodes sensitive in the near IR, 12,15 inorganic sensitizers for solar cells, 16,17 counter electrodes in dye-sensitized solar cells, 18−21 electrocatalysts, 22−24 and photocapacitors. 25 The promise of such a strong and readily available absorber has so far been met with dismal performance.…”

“…Iron pyrite (FeS 2 ) is one of the most abundant minerals in the earth’s crust, is extremely cheap to extract, , and has a bandgap and absorption coefficient that allow for a penetration depth (1/α) around 20 nm throughout the visible spectrum . Small organic molecules have also been shown to adsorb readily on its surface. , Such properties render pyrite a suspect in the origin of life on earth − and an extremely intriguing material for application in sustainable energy technologies such as photovoltaics ,− and photocatalysis. , In addition to these, more suggested applications of iron pyrite continue to come forth, including broadband photodiodes sensitive in the near IR, , inorganic sensitizers for solar cells, , counter electrodes in dye-sensitized solar cells, − electrocatalysts, − and photocapacitors …”

Synthesis of vertically aligned CaTiO3 nanotubes with simple hydrothermal method and its photoelectrochemical property

“…The nanotubes with a higher special surface area led to the higher capacity in the capture of photons and the generation of photoinduced electrons [41]. In addition, the recombination of electrons and holes could also be inhibited, which was caused by the space charge layer within the tube walls [42,43]. Therefore, the virtue of the nanotube structure was conducive to the voltage transition.…”