Quantitative framework development for understanding the relationship between doping and photoelectrochemical energy conversion of TiO₂

Abstract

Efficient energy harvesting devices are required to achieve sustainable development goals. Titania is a semiconductor that has received substantial research in pursuit of energy independence since it is an abundant,...

Surface Engineering of Anodic WO3 Layers by In Situ Doping for Light-Assisted Water Splitting

“…All tested Co-WO 3 layers exhibited lower N d values (below 1 × 10 20 cm –3 ), indicating successful substitution of W 6+ sites in WO 3 with cations with lower valence (Co 2+ /Co 3+ ), while oxygen vacancies are formed without generating W 5+ sites ( Figure 4 ). 15 , 43 , 59 , 60 Moreover, a linear dependence of capacitance of the space charge region versus applied potential ( Figure S2 ) was characterized by the presence of a positive slope of the curve, indicating the n-type semiconducting behavior of all studied materials. No clear difference in the flat band potential was observed, and slight changes (∼20 mV) are likely associated with the nanostructured nature of the films.…”

“…The obtained values of 0.27, 0.45, 0.57, and 0.64 for anodic WO 3 layers and samples obtained with the addition of 10, 30, and 100 mM CoF 2 to the electrolyte, respectively, suggest the possible presence of CoF 2 in the studied materials. Furthermore, a characteristic shift of the reflection maxima (Figure , inset) toward lower angles was detected suggesting a change in the material’s crystal structure possibly caused by difference in the size of the host lattice (66 pm) and the dopant (74.5 pm) . The composition of materials was also analyzed using Raman spectroscopy.…”

“…Furthermore, a characteristic shift of the reflection maxima ( Figure 2 , inset) toward lower angles was detected suggesting a change in the material’s crystal structure possibly caused by difference in the size of the host lattice (66 pm) and the dopant (74.5 pm). 43 The composition of materials was also analyzed using Raman spectroscopy. The collected spectra show six characteristic peaks for monoclinic WO 3 (810, 720, 328, 275, 136, and 89 cm –1 ) 44 − 46 and one low-intensity peak (189 cm –1 ) for each sample.…”