Modification of morphology and optic properties of TiO2 as photoreforming catalyst for H2 production from biomass derivatives: a review

Abstract

Abstract Hydrogen is one of the solutions to overcome the problems facing the world today, the energy crisis and a decrease in environmental quality. Its has high chemical energy per mass and its combustion only results water and does not emit greenhouse gas. Nevertheless, hydrogen doesn’t exist in nature as H2 form. Hence, it requires a sustainable production methods. Biomass (lignocellulose) and its derivatives can be renewable feedstock for producing biohydrogen via clean process i.e photoreforming. One of the keys to the success of this technology is the development of suitable photocatalysts that are able to maximize light harvesting from solar and hydrogen production. TiO2 is the establish material because of its high photocatalytic activity, not toxic, biologically and chemically inert. Its main drawback are its band gap value (ca. 3.2 eV) and fast recombination of electron–hole that detrimental to the photocatalytic activity. The alternative to overcome these problems are modification of TiO2 by nanotubes structure and doping of metals. In this paper, we will review about TiO2 nanotubes and its preparation strategies. Then, we will describe role of metal to enhance photocatalytic performance of TiO2 nanotubes. The Impact of both modification to morphology and optic properties and enhancement of H2 production from biomass and its derivatives will be study. The future direction for photoreforming of biomass and its derivatives were also suggested. Modification of Titania by nanotube structure and doping it with bi-metal consist of transition metal like Ni-Cu opens up opportunities and challenges for other researchers.