(255e) Nanostructured BaTiO3/Cu2O Heterojunction with Improved Photoelectrochemical Activity: Experimental and First-Principles Analysis

Nanostructured BaTiO₃/Cu₂O heterojunction with improved Photoelectrochemical Activity: Experimental and First-Principles Analysis

Dipika Sharma^a, Anuradha Verma^a, Anamika Banerjee^a, Anupam Srivastav^a, Vibha R. Satsangi^b, Rohit Shrivastav^a, Umesh V. Waghmare^c, Sahab Dass^a

^aDepartment of Chemistry, Dayalbagh Educational Institute, Agra-282 110 (India)

^bDepartment of Physics & Computer Sciences, Dayalbagh Educational Institute, Agra-282 110 (India)

^cTheoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560 064 (India)

* Phone: +91-9219695960.  Fax: +91-562-2801226.  E-mail: drsahabdas@gmail.com.

Study on photoelectrochemical activity of pristine BaTiO₃, Cu₂O and BaTiO₃/Cu₂O heterojunction has been carried out using DFT based band offsets and charge carriers effective mass calculations and their experimental verification. The results of DFT calculations show that BaTiO₃ and Cu₂O have staggered type band alignment after the heterojunction formation and high mobility of electrons in Cu₂O as compared to the electrons in BaTiO₃. Staggered type band edges alignment and high mobility of electrons and holes improved the separation of photo-generated charge carriers in BaTiO₃/Cu₂O heterojunction.  To validate the theoretical results experiments were carried out on pristine BaTiO₃, Cu₂O and BaTiO₃/Cu₂O heterojunction with varying thickness of Cu₂O. All samples were characterized by X- Ray Diffractometer, SEM and UV–Vis spectrometry. Nanostructured thin films of pristine BaTiO₃, Cu₂O and BaTiO₃/Cu₂O heterojunction were used as photoelectrode in the photoelectrochemical cell for water splitting reaction.  Maximum photocurrent density of 1.44 mA/cm² at 0.90 V/SCE was exhibited by 442 nm thick BaTiO₃/Cu₂O heterojunction photoelectrode. Increased photocurrent density and enhanced photoconversion efficiency, exhibited by the heterojunction may be attributed to improved conductivity and enhanced separation of the photogenerated carriers at the BaTiO₃/Cu₂O interface. The experimental results and first-principles calculations compare well, thus suggesting that such calculations have the potential to be used in screening various metal oxide heterojunction before performing the experiments thereby saving precious chemicals, time and energy.  

Keywords: Photoelectrochemical, Water splitting, heterojunction, Cu₂O, BaTiO₃

References:

 [1] Surbhi Choudhary, et al. Nanostructured bilayered thin films in photoelectrochemical water splitting - A review: International Journal of Hydrogen Energy, (2012).

[2] Dipika Sharma, Anuradha Verma, V.R. Satsangi, Rohit shrivastav, Sahab Dass Nanostructured SrTiO₃ thin films sensitized by Cu₂O for Photoelectrochemical Hydrogen Generation. International journal of Hydrogen Energy;42:,4230-4241, 2014.