Deposition of inverse opal-like TiO₂ thin film with enhanced photoelectrochemical activity by a spin-coating combined with a dip-coating method

Abstract

TiO2 thin films with an inverse opal-like structure have attracted considerable attention recently owing to their high potential for a range of applications. In this study, we demonstrated the possibility to deposit TiO2 thin films with an inverse opal-like structure from TiO2 nanoparticle-based slurry paste using a conventional spin-coating process. In addition, we also showed that the photoelectrochemical (PEC) performance of as-fabricated inverse opal-like TiO2 films can be further improved by the dip-coating process. In particular, dip-coated and untreated inverse opal-like TiO2 films exhibit photocurrent densities of ~ 66.5 µA/cm2 and ~ 40.9 µA/cm2 at 1.23 V vs. RHE, respectively. A detailed physicochemical analysis revealed that photocurrent density enhancement (~ 38.5%) in dip-coated inverse opal-like films can be attributed to a variety of factors including improved interconnection between TiO2 nanoparticles, higher crystallinity, decreased light reflection, and reduced charge carriers recombination. We strongly believe that these findings will be useful in the development of highly efficient third-generation solar cells, photocatalytic systems, electrochromic devices, and gas sensors.

Porosity-dependent photoelectrochemical activity of double-layered TiO2 thin films deposited by spin-coating method

“…In general, peaks up to ∼390 nm can be attributed to direct electron-hole recombination, whereas peaks in the blue-green range are caused by intrinsic defect states in TiO 2 lms. 22,29 The TO200 lm had a signicantly lower emission peak in the UVvisible range when compared to the TO and TO400 lms, indicating a lower recombination rate. It should be pointed out that the TO400 sample also demonstrate better PEC activity, absorbance, and a lower recombination rate when compared to the TO reference.…”

“…21-1272), respectively. 18,22 There were no other peaks observed, indicating the formation of pure anatase TiO 2 phase.…”

“…Several methods for deposition of porous TiO 2 thin lms have been reported in the literature, including spray-pyrolysis deposition, 18 the sol-gel method, 19 dip-coating, 20 inkjet printing combined with low-temperature plasma treatment, 21 and spin-coating combined with a dip-coating process. 22 Among them, the sol-gel and spin-coating methods appear to be promising due to their simplicity and versatility. However, noneven thickness and non-uniform pores that form as a result of the removal of the polymeric molecules also limit the use of TiO 2 lms prepared by the sol-gel method.…”

Construction of [NbO]6−x‐xS Structure to Change Charge Density and Regulate Spontaneous Polarization to Achieve Efficient Pyro‐Photo‐Electric Water Splitting System of NaNbO3

“…[5,6] Among the many existing efficient hydrogen production methods developed by researchers, photoelectrochemical (PEC) water splitting technology stands out among the many means of hydrogen production because of its economics, environmental friendliness and high efficiency as the best blueprint for converting solar energy into a green and sustainable energy source. [7][8][9][10] In order to maximize the PEC water splitting performance, much attention has been paid to the development of efficient photoanode materials, including TiO 2 , WO 3 , α-Fe 2 O 3 , CdS, BiVO 4 . [11][12][13][14][15][16][17][18][19][20][21] However, the enhancement of PEC performance is still limited to the semiconductor itself, which often has some drawbacks.…”

“…Most promisingly, a kind of green and renewable clean energy: hydrogen energy, is gradually entering people's view and attracting widespread attention and has become the best choice to solve the energy crisis and environmental problems [5,6] . Among the many existing efficient hydrogen production methods developed by researchers, photoelectrochemical (PEC) water splitting technology stands out among the many means of hydrogen production because of its economics, environmental friendliness and high efficiency as the best blueprint for converting solar energy into a green and sustainable energy source [7–10] . In order to maximize the PEC water splitting performance, much attention has been paid to the development of efficient photoanode materials, including TiO 2 , WO 3 , α‐Fe 2 O 3 , CdS, BiVO 4 [11–21] .…”