In-situ Construction of 2D/3D ZnIn₂S₄/TiO₂ with Enhanced Photocatalytic Performance

Abstract

To study the influence of the construction of heterojunction on the visible-light response range and the photo-generated charge carriers separation efficiency of TiO2, two dimensional/three dimensional (2D/3D) ZnIn2S4/TiO2 heterojunctions were synthesized by high-temperature calcination followed by a facile oil bath method, and were investigated for the photodegradation of Rhodamine B (RhB) and tetracycline (TC). X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were applied to investigate the composition, crystal structure, and morphology of the as-prepared specimens. UV-visible diffuse reflectance spectra (UV-vis DRS), electrochemical impedance spectroscopy (EIS), photocurrent measurement, photoluminescence (PL) spectra, and first-principles calculation were also performed to investigate the photoelectric property. The results showed TiO2 maintains the morphology of metal-organic frameworks (MOFs) with narrow visible-light response range and high photo-generated charge recombination efficiency. After coupling with ZnIn2S4 nanosheets, a larger specific surface area was obtained with offering more active sites for photocatalytic reaction. The band gap of the composite was reduced from 3.23 eV of TiO2 to 2.52 eV of ZnIn2S4/TiO2-II, and thus obtaining an extended visible-light response range and enhancing visible light utilization rate. The energy band structure acquired from the UV-vis DRS and XPS valence band spectra indicated a construction of type II heterojunction in the ZnIn2S4/TiO2 composite, and thus improving the separation and transfer efficiency of photo-generated carrier pairs, which was confirmed by the PL, EIS and photocurrent test results. Under the visible light, ZnIn2S4/TiO2 displayed significantly enhanced photocatalytic activity than bare TiO2 and ZnIn2S4. Among of ZnIn2S4/TiO2 photocatalysts, ZnIn2S4/TiO2-II possessed the highest photocatalytic degradation efficiency (93%) of RhB solution within 60 min, which was nearly 18 and 2 times higher than pristine TiO2 and ZnIn2S4, respectively. Besides, the ZnIn2S4/TiO2-II photocatalyst also showed enhanced photocatalytic activity for TC degradation than pure TiO2 and ZnIn2S4. The cycle experiment showed that the ZnIn2S4/TiO2-II photocatalyst could maintain good reusability, and it could still photodegrade 83% RhB after 5-cycle test. This work demonstrates that constructing 2D/3D ZnIn2S4/TiO2 heterojunction based on MOFs-derived TiO2 is an efficient strategy for significantly enhancing the photocatalytic activity of TiO2.

Structural, vibrational, photoelectrochemical, and optical properties of two-dimensional Ruddlesden–Popper perovskite BA2PbI4 crystals

“…In general, the flat band potential is approximately equal to the CB potential for n-type semiconductors and the VB potential for p-type semiconductors, respectively. 35 Therefore, by subtracting the optical band gap (2.25 eV) from the CB, the potential of the VB of BA 2 PbI 4 crystals with respect to Ag/AgCl is calculated to be 1.79 V vs. Ag/AgCl.…”

A ZnIn2S4@ReS2/AgInS2-based photoelectrochemical aptasensor for the ultrasensitive detection of kanamycin

“…1C, the characteristic peaks at 1022.0 eV and 1045.1 eV were attributed to Zn 2p 3/2 and Zn 2p 1/2 , respectively, indicating the existence of Zn 2+ . 22 In Fig. 1D, the characteristic peaks of In 3d 5/2 and In 3d 3/2 were located at 444.9 eV and 452.5 eV, respectively, which indicated the existence of In 3+ .…”

Facile Construction of 2D/2D ZnIn2S4-Based Bifunctional Photocatalysts for H2 Production and Simultaneous Degradation of Rhodamine B and Tetracycline

“…Among the semiconductor materials, TiO 2 , as a wide bandgap (E g ~3.2 eV) semiconductor material, is widely considered as an ideal candidate to fabricate heterojunction with ZnIn 2 S 4 due to its excellent stability, nontoxicity, and low cost [ 17 ], which has been widely applied in photocatalytic H 2 production [ 18 ], pollution degradation [ 19 ], CO 2 reduction [ 20 ], and organic synthesis [ 21 ]. More importantly, the energy band position of ZnIn 2 S 4 is above that of TiO 2 allowing for photogenerated carriers transfer between ZnIn 2 S 4 and TiO 2 , and thus coupling ZnIn 2 S 4 and TiO 2 contributes to addressing the shortfalls of ZnIn 2 S 4 [ 22 ].…”