Indium-doped ZnOas efficient photosensitive material for sunlight driven hydrogen generation and DSSC applications: integrated experimental and computational approach

Abstract

Electricity generation using simple and cheap dye sensitized solar cells and photocatalytic water splitting to produce future fuel, hydrogen, directly under natural sunlight fascinated the researchers world-wide. Herein, synthesis of indium doped wurtzite ZnO nanostructures with varying molar percentage of indium from 0.25 to 3.0% with concomitant characterization indicating wurtzite structure is reported. The shift of (002) reflection plane to higher 2θ degree with increase in indium doping thus is a clear evidence of doping of indium in zinc oxide nanoparticles. Surface morphological as well as microstructural studies of In@ZnO exhibited generation of ZnO nanoparticles and nanoplates of diameter 10-30 nm. The structures have been correlated well using computational density functional theory (DFT) studies. Diffuse reflectance spectroscopy depicted the extended absorbance of these materials in the visible region. Hence, the Photocatalytic activity towards hydrogen generation from water under natural sunlight as well as efficient DSSC fabrication of these newly synthesized materials has been demonstrated. In-doped ZnO exhibited enhanced photocatalytic activity towards hydrogen evolution (2465 μmol/h/g) via water splitting under natural sunlight. DSSC fabricated using 2% In-doped ZnO exhibited an efficiency of 3.46 % which is higher than other reported In-doped ZnO based DSSCs.

DFT Study of Hydrogen Evolution Reactions of Water Molecule with In7 and In6Al Clusters

“…Many theoretical research on indium in recent years have demonstrated that indium clusters have many great qualities in the areas of methane dehydrogenation, enhancing the stability of clusters like InnN 2 , and enhancing the photoactivity of TiO 2 [16][17][18]. Indium element also has a good performance in photocatalytic reaction, studies have shown that ZnInxSy, ZnO, and other clusters doping with appropriate amount of In can improve the photocatalytic hydrogen evolution activity [19][20][21]. To expand the research on hydrogen production from cluster dissociation of water, in view of the excellent properties of In clusters in many aspects, this research will start with In clusters to study the hydrogen evolution principle of the reaction between In clusters and H2O, and explore its performance in dissociating water to produce hydrogen.…”