Monolithic ag-mt dispersed z-scheme pcn-tio2 heterojunction for dynamic photocatalytic h2 evolution using liquid and gas phase photoreactors

Abstract

Fabricating montmorillonite (Mt) dispersed Ag/pCN-TiO2 heterojunction for stimulating photocatalytic H2 evolution using two/three phases photo-reactor systems has been investigated. Using Ag–Mt/pCN–TiO2 composite in three-phase, H2 rate of 667 μmolh−1 was obtained, much greater than TiO2-based samples due to superior charges separation with Ag SPR and Mt mediated effect. Among parameters, 0.15 g catalyst loading at pH 7 gives highest H2 yield with glycerol sacrificial reagents. More interestingly, liquid system with glycerol gave best H2 rate while gas-phase with methanol encouraged H2 productivity. Furthermore, H2 rate increased to 8230 μmolh−1 using two-phase monolith reactor, 9.01 and 12.34 times greater than two-phase fixed-bed and three-phase slurry systems. Comparatively, highest AQY and SY of 39.85% and 54.86 μmolh−1cm−3 were obtained using monolith. This superior efficiency was due to efficient photon-flux consumption, effective mass-transfer and large light-fluxed. These findings would be fruitful for further development for clean hydrogen production through photocatalytic water splitting.