Photocathodic Protection of 304 Stainless Steel by Bi2S3/TiO2 Nanotube Films Under Visible Light

Abstract

We report the preparation of TiO2 nanotubes coupled with a narrow bandgap semiconductor, i.e., Bi2S3, to improve the photocathodic protection property of TiO2 for metals under visible light. Bi2S3/TiO2 nanotube films were successfully synthesized using the successive ionic layer adsorption and reaction (SILAR) method. The morphology and structure of the composite films were studied by scanning electron microscopy and X-ray diffraction, respectively. UV–visible diffuse reflectance spectra were recorded to analyze the optical absorption property of the composite films. In addition, the influence of Bi2S3 deposition cycles on the photoelectrochemical and photocathodic protection properties of the composite films was also studied. Results revealed that the heterostructure comprised crystalline anatase TiO2 and orthorhombic Bi2S3 and exhibited a high visible light response. The photocurrent density of Bi2S3/TiO2 was significantly higher than that of pure TiO2 under visible light. The sensitization of Bi2S3 enhanced the separation efficiency of the photogenerated charges and photocathodic protection properties of TiO2. The Bi2S3/TiO2 nanotubes prepared by SILAR deposition with 20 cycles exhibited the optimal photogenerated cathodic protection performance on the 304 stainless steel under visible light.

Bi2Se3 Sensitized TiO2 Nanotube Films for Photogenerated Cathodic Protection of 304 Stainless Steel Under Visible Light

“…3 d, the O 1s semaphores matched with two Gaussian peaks: the maximum at the lower binding energy (530.0 eV) was attributed to the lattice oxygen (O L ) in Bi 2 Se 3 /TiO 2 nanocomposites and the second at the higher binding energy (531.5 eV) was derived from the adsorbed oxygen (O A ), including weak bonding oxygen or hydroxyl groups. The existence of O A was due to the generation of oxygen vacancies on the surface of the nanocomposites, which might improve the photoelectric conversion properties of Bi 2 Se 3 /TiO 2 nanocomposites in photocathodic protection [ 53 ]. Figure 3 e shows that the 4f 7/2 asymmetric peak for Bi resolved into two peaks (157.5 and 159.4 eV), with the Bi 4f 5/2 spectrum similarly divided into two bands at 162.8 and 164.7 eV, respectively.…”

Enhanced Visible-Light Photoelectrochemical Conversion on TiO2 Nanotubes with Bi2S3 Quantum Dots Obtained by in Situ Electrochemical Method

“…One of the most used is the successive ionic layer adsorption and reaction (SILAR) method. 17,18 Li et al 17 attached Bi 2 S 3 nanoparticles to TiO 2 NT films enhancing the photocurrent when compared to pristine TiO 2 NTs. Using the same technique, Zumeta-Dubéet al 19 described the sensitization of the TiO 2 NTs with Bi 2 S 3 nanoparticles; however, in the presence of sodium ions the stability of the system decreases, compromising its photovoltaic properties.…”

“…These QDs are a powerful tool in optoelectronic devices due to their absorption in the visible and near-infrared region. − Different methodologies are employed to sensitize the TiO 2 with Bi 2 S 3 semiconductor. One of the most used is the successive ionic layer adsorption and reaction (SILAR) method. , Li et al attached Bi 2 S 3 nanoparticles to TiO 2 NT films enhancing the photocurrent when compared to pristine TiO 2 NTs. Using the same technique, Zumeta-Dubé et al described the sensitization of the TiO 2 NTs with Bi 2 S 3 nanoparticles; however, in the presence of sodium ions the stability of the system decreases, compromising its photovoltaic properties.…”

Research progress of TiO2 photocathodic protection to metals in marine environment

“…The electric fi eld increases the separation of photogenerated carriers and then reinforces the photoelectrochemical properties (Hu et al, 2017; et al, 2017a; Guan et al, 2018b). The narrow bandgap doping mechanism is shown in Fig.8 (Li et al, 2017a;Yang et al, 2019). MnS has excellent photoelectric performance and is mainly used as a buff er material, photoelectric device and magnetic component of many important diluted magnetic semiconductors.…”

“…Hitherto, based on these strategies, researchers have synthesized TiO 2 nanotube photoanodes and modifi ed them by increasing the surface area, doping, sensitizing quantum dots, and combining diff erent semiconductors to extend their functionalities in the visible range. Coupling with narrow-bandgap semiconductors, metals and nonmetals are used for photocathodic protection, and the protected metal tends to be polarized into a safe range under visible light (Li et al, 2017a;Bu et al, 2018).…”