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Graphical abstract Highlights • g-C 3 N 4 /SrTiO 3 nanocomposites were synthesized with strong interactions between g-C 3 N 4 and SrTiO 3. • g-C 3 N 4 /SrTiO 3 nanocomposites had superior photocatalytic performance, for advantageous interfacial effects. • The built-in electric field in the interface of nanocomposites was illustrated by XPS results and DFT calculations. • The possible photocatalytic mechanism was proposed. Abstract The g-C 3 N 4 /SrTiO 3 nanocomposite is an important material in photocatalysis, but little attention has been paid to their interfacial interaction in photocatalytic reaction. Herein, we prepare the g-C 3 N 4 /SrTiO 3 nanocomposites via a two-step mechanically milling and calcination process. The composite exhibited the highest H 2 evolution activity superior to that of the pure g-C 3 N 4 and SrTiO 3 in the visible light. The results of UV–vis DRS, PL and photoelectrochemical measurements demonstrated that g-C 3 N 4 /SrTiO 3 exhibited more visible light adsorption and faster photo-generated charge transfer. Furthermore, the interfacial electronic structures of g-C 3 N 4 /SrTiO 3 nanocomposites were thoroughly characterized. According to the XPS and DFT results, with the help of a strong built-in electric field presenting in the g-C 3 N 4 /SrTiO 3 interface, the photo-generated electrons flow to the SrTiO 3 from g-C 3 N 4 , leading to the highly-efficient electron separation and more H 2 O molecules photo-reduction to H 2. This work explicates the significant role of built-in electric field in H 2 evolution on g-C 3 N 4 /SrTiO 3 photocatalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bi 2 O 2 CO 3 /biochar nanocomposites were firstly synthesized and reported. • Bi 2 O 2 CO 3 /biochar had good adsorption and photocatalytic activity for tetracycline. • Biochar facilitated the separation of photo-induced carriers in the composites. Adsorption and photodegradation are two widely studied wastewater treatment technologies. In this work, we have firstly prepared the bismuth oxycarbonate (Bi 2 O 2 CO 3) and biochar nanocomposites for synergistic adsorption-photodegradation of tetracycline (TC). It was found that Bi 2 O 2 CO 3 and biochar composites exhibited stronger adsorption capacity and photocatalytic activity compared to Bi 2 O 2 CO 3. Among them, Bi 2 O 2 CO 3 /2.5 wt% biochar possessed the highest adsorption capacity for TC (173.0 mg/L) and the best combined removal rate of TC (84.7 %) in 60 min by adsorption and photodegradation, which were 1.9 times and 1.5 times that of Bi 2 O 2 CO 3 , respectively. The biochar in the composite increased the specific surface area, promoted the adsorption of TC, facilitated charge transfer capability, thereby enhanced the photocatalytic activity of composites. The effects of experimental parameters (temperature, co-existing ions, and initial pH) on TC degradation were examined. Electron spin resonance (ESR) and trapping experiments of free radical confirmed that 1O 2 , •O 2 − and h+ were the main species in photocatalytic degradation. The potential degradation pathways were proposed based on liquid chromatograph mass spectrometer (LC-MS) test of the intermediates of TC degradation. It is hoped that this work not only represents the significantly importance of biochar in photocatalytic wastewater treatment, but also promotes further interests in design synergistic adsorption-photodegradation materials. [ABSTRACT FROM AUTHOR]

A series of TiO2 nanosheets are prepared with different amounts of AgNO3 and HF solution through a solvothermal process. The samples are characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), laser Raman spectroscopy (LRS), electron paramagnetic resonance (EPR), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). From the results it is clear that the added HF solution inhibits the crystallite size growth in the [001] direction, and induces the formation of the TiO2 nanosheets with highly exposed (001) facets. There is a strong interaction between the Ag nanoparticles and the TiO2 support. The (Ag,F)-modified TiO2 catalyst exhibits high activity of MB photodegradation under both UV light and visible light irradiation. Two mechanisms of photocatalysis under UV light and visible light irradiation were discussed and proposed. It is indicated that the strong interaction between the Ag nanoparticles and the TiO2 support improves the photocatalytic activity of TiO2 nanosheets. [ABSTRACT FROM AUTHOR]

In this work, a series of Cu 2 O–modified Bi 2 O 3 nanospheres with perfect visible-light catalytic activity were successfully synthesized via the two-step method. The obtained products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and X-ray photoelectron spectroscopy (XPS). In the catalysts of Cu 2 O–modified Bi 2 O 3 nanospheres, Cu 2 O was dispersed on the surface of Bi 2 O 3 nanospheres. All of Cu 2 O–modified Bi 2 O 3 nanospheres showed uniformly nanospheres with the size of 80–150 nm, and exhibited enhanced photocatalytic activity in the degradation of Rhodamine B. The higher BET surface area, the band gap narrowing, and the interfacial charge transfer effect were considered to cause the excellent photocatalysis of Cu 2 O loading Bi 2 O 3 samples. Furthermore, the possible photocatalysis mechanism was proposed. [ABSTRACT FROM AUTHOR]

• Adsorption kinetic rate of dye on g-C 3 N 4 was faster than those of photodegradation processes. • Surface photodegradation kinetic rate of dye adsorbed on g-C 3 N 4 was faster than that in solution. • Synergy between adsorption and photodegradation of dye by g-C 3 N 4 was confirmed and elucidated. • Modified Elovich model was the best to simulate the integrated adsorption and photodegradation kinetics. The synergy between adsorption and photocatalysis has been well recognized in contaminant photodegradation; however, the governing mechanism is still not clear. The main objective of this work is to understand the kinetic processes of synergic adsorption-photocatalysis of graphitic carbon nitrate (g-C 3 N 4), a visible light responsive photocatalyst with a planar graphitic-like structure, in organic contaminant removal. An anionic dye Reactive Red 120 (RR120), which has six sulphonate groups and a complex aromatic molecular structure, was selected as a model contaminant compound. A range of experiments were conducted to determine the kinetics of adsorption, photodegradation, and the integrated process. Various kinetic models were used to simulate and interpret the experimental data and thus to unveil the governing mechanisms. The integrated adsorption and photodegradation of the dye by g-C 3 N 4 was mainly controlled by: 1) adsorption of dye onto g-C 3 N 4 surface, 2) photodegradation of dye in bulk solution, and 3) photodegradation of adsorbed dye on g-C 3 N 4 surface. Both experimental and modeling results showed that the adsorption kinetic rate (3.37 min−1) was faster than the photodegradation kinetic rates. In addition, the surface photodegradation kinetic rate of adsorbed dye (0.149 min−1) was faster than that in solution (0.005 min−1). Adsorption process thus can promote the photodegradation of contaminants by g-C 3 N 4. On the other hand, photodegradation of dye-laden g-C 3 N 4 regenerated its adsorption capacity for multiple times, suggesting photocatalysis process can also promote the adsorption of contaminates on g-C 3 N 4. [ABSTRACT FROM AUTHOR]

• The superhydrophobic surface was prepared by a simple impregnation method; • The samples showed relatively good photocatalytic degradation of organic dyes under light conditions;The samples exhibit excellent superhydrophobicity and thermal conductivity. • The samples showed physical/chemical/mechanical stability in harsh environments; • The samples have relatively excellent work-cycling ability. Water resources are increasingly being damaged by human activities, and it is crucial to deal effectively with polluted water resources. Due to the diversity of pollution sources (oil, organic dyes, and other complex pollutants), it makes sense to develop a material that can handle these pollutants simultaneously. In this article, we construct a simple and fast method to fabricate multifunctional superhydrophobic polyurethane sponges (PU). A superhydrophobic composite coating constructed from ZIF-8, polydimethylsiloxane (PDMS), and stearic acid (SA) was attached to the surface of the polyurethane sponge by a simple impregnation method. Through the above process, we have successfully integrated oil–water separation, photocatalysis, and superhydrophobicity into a polyurethane sponge. The results showed that the PDMS/SA/ZIF-8 polyurethane sponge (PSZPU) had a high hydrophobicity angle (162.9 ± 1.1°). In addition, PSZPU maintains high oil–water separation performance (mean value of separation efficiency > 94.24 %) and superhydrophobicity after oil–water separation cycling tests and a series of harsh environmental tests in acidic and alkaline solutions, high temperatures, abrasion, and UV aging irradiation. Overall, the creation of PSZPU provides a new application for superhydrophobic sponges in water resource treatment. [ABSTRACT FROM AUTHOR]

The superhydrophobic coating blocks a certain air layer between the solid surface and the liquid, thereby changing the interaction between the surface and water, and has potential applications in enhancing buoyancy and drag reduction. Consequently, a superhydrophobic coating designed to reduce drag (the contact angle was up to 168°) was prepared in this study. The coating was applied to copper mesh by spraying a mixed solution comprising ZIF-8 particles, waterborne polyurethane, and a silane coupling agent, resulting in a significant enhancement of load capacity. The superhydrophobic coating can change the contact mode between the copper mesh and water, leading to a remarkable sevenfold increase in the maximum load capacity when compared with the uncoated sample, primarily due to its' increased buoyancy. In addition, the self-made superhydrophobic model ship exhibited an impressive drag reduction efficiency of up to 36 %, indicating that it has significant drag reduction capability. It's worth noting that once water enters, the superhydrophobic spheres will form a gas cavity, which is critical for the coating's drag reduction capability. The self-cleaning property of this superhydrophobic composite coating is highly promising. Moreover, it can also purify seawater by utilizing ZIF-8's photocatalytic activity to degrade organic contaminant. Therefore, in the context of actual ships and underwater vehicles, this superhydrophobic coating holds potential as a relevant strategy for enhancing buoyancy and reducing drag, thus offering commercial value. [Display omitted] • ZIF-8/POTS coatings were prepared by simple chemical modification and spraying technology. • The WCA and SA of the Zif-8/pots coating were 168 ± 1° and 4°, respectively. • The coating exhibits excellent self-cleaning and photocatalytic properties. • The coating exhibits excellent floating and drag reduction properties. [ABSTRACT FROM AUTHOR]

In this work, CeO 2 nanocubes hybridized g-C 3 N 4 composites had been facilely synthesized to investigate the interfacial effects on photocatalytic water splitting. The c-CeO 2 /g-C 3 N 4 composites exhibited the superior photocatalytic hydrogen evolution under visible light irradiation. The optimal c-CeO 2 loading content was 5 wt%, with the H 2 evolution of 4300 μmol g −1 for 5 h illumination, higher than that of pristine CeO 2 , g-C 3 N 4 and irregular CeO 2 nanoparticles/g-C 3 N 4 . Moreover, UV–vis DRS, PL spectra and photoelectrochemical measurements demonstrated that 5 wt% c-CeO 2 /g-C 3 N 4 composite possessed more visible light adsorption and faster charge transfer, which was attributed to the stronger interfacial effects through the presence of the hydrogen bond and p-π hybrid between c-CeO 2 {100} and g-C 3 N 4 , revealed by the FT-IR and XPS results. The work suggested that engineering the structures of the CeO 2 and g-C 3 N 4 interface could be an effective strategy to obtain excellent photocatalysts. [ABSTRACT FROM AUTHOR]