Mesoporous Carbon Nitride‐Tungsten Oxide Composites for Enhanced Photocatalytic Hydrogen Evolution

Abstract

Composites of mesoporous polymeric carbon nitride and tungsten(VI) oxide show very high photocatalytic activity for the evolution of hydrogen from water under visible light and in the presence of sacrificial electron donors. Already addition of very small amounts of WO3 yields up to a twofold increase in the efficiency when compared to bulk carbon nitrides and their composites and more notably even to the best reported mesoporous carbon nitride-based photocatalytic materials. The higher activity can be attributed to the high surface area and synergetic effect of the carbon nitrides and the WO3 resulting in improved charge separation through a photocatalytic solid-state Z-scheme mechanism.

IrO2 and Pt Doped Mesoporous SnO2 Nanospheres as Efficient Electrocatalysts for the Facile OER and HER

“…However, the high cost and less abundance of Pt has motivated the researchers for alternative electrocatalyst for HER. [26] Further, it is necessary to avoid the carbon support by low cost and earth-abundant metal oxide based materials as support to enhance the durability of the catalyst. Metal oxides have the potential to be explored as substitute catalyst support due to their added advantages like high surface area, thermodynamic stability and possibility of strong interaction with metallic nanoparticles, [27] which in turn could help in avoiding the agglomeration of the nanoparticle and thus to retain the number of active sites measure at the catalyst surface.…”

Active removal of waste dye pollutants using Ta3N5/W18O49 nanocomposite fibres

“…By adopting such a two-photon photocatalytic mechanism, the quantum efficiency of the catalyst may be enhanced due to improved separation of electrons and holes within the system 41–52 ; one common example of this effect is known as a “Z-scheme”, wherein electron-hole recombination within each material is suppressed due to preferential recombination between the conduction electrons of one component and valence holes of the other 46–52 . In the present investigation, a solvothermal approach 22, 53 is adapted to grow tungsten(VI) sub-oxide nanostructures on the surface of Ta 3 N 5 nanoparticles, thereby forming a nanocomposite of the two materials.…”

Hydrogen Evolution Reaction in a Large‐Scale Reactor using a Carbon Nitride Photocatalyst under Natural Sunlight Irradiation

“…[1][2][3] Hydrogeni sahigh energy carrier and is currently produced in large quantities by steam reforming of methane and coal gasification. [9][10][11][12][13][14][15][16] Thei ntroductiono fp orosity into g-CN materials,t hat is,i ncreasing the accessible surface area, has been shown to be ah ighly promising route to achieve higher H 2 evolution activity. However, it should be noted that ap hotoelectrochemical system generally involves ar ather complex cell setup and furthermorer equires the application of an externalb ias and an expensive platinumc ounter electrode.A ttempts to scale up such devices are therefore always limited due to cost and technological considerations.O nt he other hand, the direct photocatalytic conversion of water into hydrogen and oxygen requires only aw ater reservoir containing the photocatalyst either as ap owder or as ac atalytic coating on substrates and therefore offers an alternative to generate H 2 in am ore costand energy-efficient manner.…”

“…However, it should be noted that ap hotoelectrochemical system generally involves ar ather complex cell setup and furthermorer equires the application of an externalb ias and an expensive platinumc ounter electrode.A ttempts to scale up such devices are therefore always limited due to cost and technological considerations.O nt he other hand, the direct photocatalytic conversion of water into hydrogen and oxygen requires only aw ater reservoir containing the photocatalyst either as ap owder or as ac atalytic coating on substrates and therefore offers an alternative to generate H 2 in am ore costand energy-efficient manner. [9][10][11][12][13][14][15][16] Thei ntroductiono fp orosity into g-CN materials,t hat is,i ncreasing the accessible surface area, has been shown to be ah ighly promising route to achieve higher H 2 evolution activity. In this regardp robably the most notable photocatalyst, using visible light as energy source,i sR h 2Ày Cr y O 3 /(Ga 1Àx Zn x )(N 1Àx O x ), which was reported recently and applied as as ilica suspension on a5cm 5 cm glass plate.…”