Facile synthesis of noble-metal free polygonal Zn2TiO4 nanostructures for highly efficient photocatalytic hydrogen evolution under solar light irradiation

• Published in: International journal of hydrogen energy Vol. 43; no. 29; pp. 13145 - 13157
• Main Authors: Manchala, Saikumar, Nagappagari, Lakshmana Reddy, Muthukonda Venkatakrishnan, Shankar, Shanker, Vishnu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 19-07-2018
• Subjects: Hydrogen evolution; Noble-metal free; Polygonal Zn2TiO4; TiO2; ZnO; ZnO; Noble-metal free; Hydrogen evolution; Polygonal Zn2TiO4; TiO2
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2018.05.035

Designing of noble-metal free and morphologically controlled advanced photocatalysts for photocatalytic water splitting using solar light is of huge interest today. In the present work, novel polygonal Zn2TiO4 (ZTO) nanostructures have been synthesized by citricacid assisted solid state method for the first time and synthesized nanostructures were characterized by using various techniques like PXRD, UV-Vis-DRS, PL, FT-IR, BET, FE-SEM and TEM for their structural, optical, chemical, surface and morphological properties. The PXRD and UV-Vis-DRS analysis show the existence of cubic and tetragonal phases. FE-SEM and TEM results confirm the formation of polygonal ZTO nanostructures. Synthesised ZTO nanostructures have been potentially applied for solar light-driven photocatalytic hydrogen evaluation from water splitting and compare the photocatalytic activity with synthesized conventional Zn2TiO4 and commercially available TiO2, ZnO photocatalysts. A high rate of 529 μmolh−1g−1 solar light-driven photocatalytic H2 evolution has been achieved by using a small amount (5 mg) of polygonal Zn2TiO4 nanostructures from glycerol-water solution. The enhanced photocatalytic performance of the polygonal Zn2TiO4 nanostructures compare to conventional Zn2TiO4 under solar light irradiation is due to the large surface area and low recombination rate. However having the same bandgap, the polygonal Zn2TiO4 nanostructures have shown enhanced photocatalytic performance than that of commercially available TiO2, ZnO photocatalysts.
•Citric acid assisted solid state synthesis of novel polygonal Zn2TiO4 nanostructures for the first time.•Synthesized polygonal Zn2TiO4 nanostructures show superior morphological and surface properties.•Polygonal Zn2TiO4 nanostructures seem to be a better photocatalyst for H2 evolution under solar light.•Comparison of photocatalytic activity with commercially available TiO2, ZnO.