Photocatalytic hydrogen production over nanostructured mesoporous titania from olive mill wastewater

In this study, nanostructure mesoporous titania (TiO2) was prepared using sol–gel method from titanium tetrachloride. The prepared titania was characterized by X-ray diffraction (XRD). The textural and surface analysis was carried out using nitrogen adsorption–desorption technique. Also, the photocatalytic degradation of olive mill wastewater (OMW) with simultaneous hydrogen production was studied. The influence of catalyst dose and pH value of wastewater on the degradation of organic pollutants in wastewater and on the amount of evolved hydrogen was investigated. It was observed that the maximum amount of evolved hydrogen at a TiO2 dose of 2 g/L and a solution pH value of 3 was (851 mL H2) 38 mmol after 2 h of reaction. On the other hand, chemical oxygen demand (COD) was reduced by 92%. Based on the obtained results, a new process for H2 production from wastewater can be achieved by coupling degradation of organic pollutants with photocatalytic H2 production. The process also provides a method for degradation of organic pollutants with simultaneous H2 production.

Research Highlights
► Preparation of active mesoporous TiO2 with large surface area and nanoparticle size.
► Hydrogen production was affected by pH, reaction time and catalyst loading.
► Hydrogen production over nanotitania enhanced due to presence of organic pollutants.
► kapp was highly affected by the pH value of wastewater and TiO2 loading.
► H2 production from wastewater can be coupled with degradation of organic pollutants.