High Visible Light Absorption Research Articles

Popcorn-stick-like NH2-UiO-66/TiO2 nanotube nanocomposites toward optimized photocatalytic carbon oxidation with nitrogen dioxide

Developing photocatalytic technologies for pollutants removal with high harmless product selectivity is a significant challenge. Construction and optimization of nanocomposites junction with appropriate band alignments is an effective method for achieving this objective. Herein, a unique popcorn-stick-like NH2-UiO-66/TiO2 nanotube nanocomposites with staggered band alignment is fabricated. The small metal organic frameworks (MOFs) particles with diameters around 20 nm are uniformly dispersed on the surface of TiO2 nanoplates, creating a popcorn-stick-like structure. The resulting as-synthesized nanocomposites photocatalysts show distinguished photocatalytic activity for simultaneous removal of carbon particles and nitrogen dioxide with 100% NO2 conversion and 99% N2 selectivity, about 3.9 times higher than that of pristine TiO2. The significant enhancement is attributed to the rapid charge separation and transfer in TiO2 and NH2-UiO-66 interface and the visible light absorption. The enhanced charge transfer follows double charge transfer mechanism, which is confirmed by surface photovoltage spectroscopy, photoluminescence, transient photocurrent measurements, and electrochemical impedance spectroscopy. This study demonstrates the potential for the simultaneously removal of two pollutants using the composite of TiO2 and MOF materials with high surface area and visible light absorption ability, thereby providing the possible applications of NH2-UiO-66/TiO2 composites in environmental remediation including air purification and wastewater treatment.

Strong Intermixing Effects of LFO1-x/STOx toward the Development of Efficient Photoanodes for Photoelectrocatalytic Applications.

Aiming to improve the photocatalytic properties of transition metal perovskites to be used as robust photoanodes, [LaFeO3]1-x/[SrTiO3]x nanocomposites (LFO1-x/STOx) are considered. This hybrid structure combines good semiconducting properties and an interesting intrinsic remanent polarization. All the studied samples were fabricated using a solid-state method followed by high-energy ball milling, and they were subsequently deposited by spray coating. The synthesized compounds were demonstrated to possess orthorhombic (Pnma) and cubic (Pm3¯m) structures for LFO and STO, respectively, with an average grain size of 55-70 nm. The LFO1-x/STOx nanocomposites appeared to exhibit high visible light absorption, corresponding to band gaps of 2.17-3.21 eV. Our findings show that LFO0.5/STO0.5 is the optimized heterostructure; it achieved a high photocurrent density of 11 μA/cm2 at 1.23 V bias vs. RHE and an applied bias photo-to-current efficiency of 4.1 × 10-3% at 0.76 V vs. RHE, as demonstrated by the photoelectrochemical measurements. These results underline the role of the two phases intermixing LFO and STO at the appropriate content to yield a high-performing photoanode ascribed to efficient charge separation and transfer. This suggests that LFO0.5/STO0.5 could be a potential candidate for the development of efficient photoanodes for hydrogen generation via photoelectrocatalytic water splitting.

Single-step synthesis of 1D/3D- BiYO3/BiOI direct Z-scheme heterostructure for the remediation of wastewater

In this work, a visible-light responsive BiYO3/BiOI nanocomposite photocatalyst with various amounts (1, 2, 3 wt %) of BiYO3 was synthesized by a solvothermal process. Furthermore, the prepared nanocomposite was investigated by various spectroscopic analysis, like X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (UV-DRS), photoelectrochemical and photoluminescence (PL) studies. The structural morphology study explored BiYO3 1D-nanorods are anchored on the surface of 3D-marigold flower-like structure of BiOI. Among different ratio of BiYO3 loaded over the samples, the optimized BYBI-2 nanocomposite seem to reveal much higher (83%) photocatalytic efficiency than the pure BiOI and BiYO3. In addition, the recycling tests too indicated that the optimized BYBI-2 nanocomposite is more robust, stable and reusable material for photocatalytic performances. The obtained rate constant value on the photodegradation of BYBI-2 nanocomposite is 0.02758 min−1 and has about 3.5 and 6.5 times larger than the pure BiOI (0.00808 min−1) and BiYO3 (0.00424 min−1) proportionately. The augmented photocatalytic activity of catalyst could be owed to the high visible-light absorption capability and the efficient separation of the charges. The radical trapping experiments too corroborated the vital role of h+ and •OH in the photocatalytic degradation of methylene blue (MB). According to the findings, a conceivable ZFTIR-scheme degradation mechanism of BiYO3/BiOI composite for detoxifying MB under 60 min of visible light irradiation has been presented. Thus, we considered that the as-synthesized material could be distinguished photocatalytic material for wastewater treatment.

Photocurrent performance and enhancement of opto-electronic properties of spray pyrolysis deposited ZnO thin films via V-doping

This study reports on the deposition of highly transparent conducting n-type zinc oxide (ZnO) thin films on FTO substrates, via an optimized doping process. Our work is focused on doping zinc oxide with vanadium (V) using spray pyrolysis technique and ensure the synthesis of nanoparticles-shaped ZnO, with an improved optical, microstructural and electrical properties for solar cells applications, as optical window material. Undoped and V-doped ZnO thin films, with careful optimized amounts (2, 4, 6 and 8 at.%), were grown at maintained 550∘C pre-heated substrate during the deposition process, which enables us to obtain nano-sized ZnO particles. We proved that 4 at.% is the optimum V content that enhances the crystallinity of the grown thin film noticeably. With an average transmittance of 80%, the deposited thin films revealed high transparency in the visible domain with a slight decrease in optical transmission which might result from additional scattering. UV-Visible analysis showed that increasing V amounts, a resulting decrease in the energy bandgap ([Formula: see text]) is obtained from 3.26[Formula: see text]eV to 3.17[Formula: see text]eV for 4 at.% of V content. Moreover, deep level defects in zinc oxide can be reduced with vanadium doping and consequently strengthen the UV emission. The UV emission peak intensity rises with increasing V-doping amount then decreases slightly at 8% of V content. The electrical properties measurements showed a decrease in resistivity from 2.8 10[Formula: see text][Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm to 0.9 10[Formula: see text][Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm when doping with 4 at.% of V. The crucial effect of the V-doping of ZnO was also demonstrated via the enhancement of carrier mobility that attains 38.5[Formula: see text]cm2/V[Formula: see text]⋅[Formula: see text]s at the optimum vanadium content. The photocurrent analysis revealed much higher visible light absorption in the V-doped zinc oxide thin films than that of undoped film. The photocatalytic activity enhancements are attributed to the lower recombination rate of the photogenerated electron-hole pairs, the narrowed bandgap, yielding a higher photocatalytic performance.

Preparation of a Novel Nanostructured Lead Titanate Composite Photocatalyst and Its Degradation of Organic Dyes under Visible Light

Photocatalytic dye degradation is an energy-saving, environmentally friendly and sustainable way of managing potentially toxic wastewater from the textile industry. PbTiO3 was prepared using a solid-state reaction method, and an optimal ratio of PbTiO3/TiO2/g-C3N4 photocatalyst was synthesized using the sol-gel method to test its ability to decompose organic dyes. Methylene blue (MB) was selected as a target dye to test the photocatalytic effects. SEM results showed that the synthesis of a PbTiO3/TiO2/g-C3N4 photocatalyst yielded a unique nano structure with many surface pores. UV-Vis analysis demonstrated that the novel composite photocatalyst had higher visible light absorption, and a reduced energy gap. Experimental results showed that of the samples tested, PTO/TO/CN 1.0 showed the best photocatalytic effect on the removal of MB. Under visible light, the removal rate of MB by PTO/TO/CN 1.0 was up to 98.79%. The novel PTO/TO/CN 1.0 photocatalyst exhibited relatively high MB adsorption and had a high photocatalytic ability.

Enhancement of visible light organic dyes photodegradation using TiO2 (001)/Graphene oxide nanocomposite

Photodegradation has been considered one of the most promising ways to treat wastewater. In this work, TiO2 (001)/Graphene Oxide (GO) nanocomposite has been successfully synthesized using hydrogen fluoride as a crystal-directing agent towards (001) facets. The nanocomposite was characterized by FTIR, XRD, Raman, HR-TEM, and diffuse reflectance spectra (DRS). Based on the result, the TiO2 (001) was decorated on the surface of the GO sheet with high absorption of visible light. In addition, as-prepared TiO2 (001)/GO nanocomposite provides a synergistic effect by increasing dye degradation activity with 95% and 99% removal rates for the photodegradation of methylene blue and crystal violet dyes, respectively, under LED irradiation for 10 min. The photodegradation kinetics of TiO2 (001)/GO was also successfully modeled and was found to follow the pseudo-first order kinetic. The enhanced photodegradation of the TiO2 (001)/GO nanocomposite attributed to the excellent synergy between TiO2 (001) nanoparticles and GO, which results in the highly efficient photocatalyst for removing organic pollutants in water.

A PN-type CuO@TiO2 nanorods heterojunction for efficient PEC water splitting: DFT model and experimental investigation on the effect of calcination temperature

Heterojunction formation between two dissimilar semiconductors is a promising strategy to improve the harvesting of the visible photons and separation of the electron-hole pairs in semiconductor-based photocatalysts. Herein, the interfacial characteristics of TiO2 rutile (011) surface and Cu-MOF derived cupric oxide (CuO) were examined via simulation and experimental approaches for solar hydrogen production. The results illustrate the formation of van der Waals type heterojunction (Type-II) with higher visible light absorption and lesser charge transfer resistance. This was attributed to significant charge transfer from CuO to the TiO2 surface, establishing a PN-type heterojunction. The valence band maxima and conduction band minima of the designed heterostructure matched well with redox potential of water even with the considerable bandgap reduction around 1.66 eV. Furthermore, the hybrid photocatalyst calcined at 450 °C produced the highest hydrogen production at 32,766 μmol g−1 h−1. The outcome thus provides a valuable insight in developing suitable photocatalysts for practical production of hydrogen through photo-electrolysis technique.

Well-designed bio-based waste sewage sludge (WSS) cocatalyst coupled g-C3N4 nanorods with the synergistic effect of sludge metals (M=Ni, Cu, Al, Mn) to construct ternary heterojunction for solar H2 production

A ternary heterojunction of waste sewage sludge (WSS) as a co-catalyst with sludge metals (M = Ni, Cu, Zn, Mn, and Fe) elements anchored over g-C3N4 nanorods (g-CNNR) was fabricated for photocatalytic H2 evolution under visible light. The innovative WSS enables H2 production of 25 μmol h−1 g−1 due to the presence of oxidized (Fe2O3, ZnO) and other metals to promote charge carrier separation. The g-CNNR with WSS provides good interface interaction with proficient charge carrier separation and can potentially enhance photocatalytic activity, as confirmed by standard metal elements. Using a 10% WSS/g-CNNR nanotexture, a maximum H2 yield of 195 μmol h−1 g−1 was achieved, 4.5 and 7.8 times higher than pure g-CNNR and WSS, respectively. The finding reveals that adding WSS significantly increases the photocatalytic H2 generation under visible light. This noticeable improvement was caused by the formation of heterojunction, which separated charge carriers, higher visible light absorption and synergistic effects of multiple elements in WSS which contributed to promote solar hydrogen evolution. Furthermore, the ultrasonic approach was found promising to enhance H2 evolution approximately two-fold than of bulk WSS/g-CNNR due to more light penetration and separation of charge carriers. Among the sacrificial reagents, methanol enables a higher yield of H2 with more stability in multiple cycles. The findings of this work would be beneficial for further investigation on the use of WSS as a cocatalyst and support in different energy and environment applications.

Co+2, Ni+2 and Cu+2 incorporated Bi2O3 nano photocatalysts: Synthesis, DFT analysis of band gap modification, adsorption and photodegradation analysis of rhodamine B and Triclopyr

This study deals with the fabrication of metal ion (M = Co+2, Ni+2, and Cu+2) doped- Bi2O3 photocatalysts by solution combustion method. All the synthesized materials were characterized and analysed with the help of XRD, FESEM, EDX, HRTEM, UVDRS, Zeta potential, PL, and LCMS techniques for the structural, morphological, surface charge, optical and degradation pathways characteristics. Synthesized compounds were used for the decontamination (adsorption and degradation) of two organic pollutants namely Rhodamine B and Triclopyr. Adsorption aspects of the pollutants were studied in terms of different isotherm, kinetic and thermodynamic models. Adsorption phenomenon was best fitted with the Freundlich (R2 = 0.992) and Langmuir isotherm (R2 = 0.999) models along with pseudo second order model of kinetics for RhB and TC, respectively. Moreover, the thermodynamic parameters indicated exothermic and endothermic adsorption (ΔH ° (−7.19 kJ/mol) for RhB) and (ΔH ° (52.335 kJ/mol) for TC), respectively. Evaluated negative values of ΔG ° indicated spontaneous adsorption with most favourable at 298 K and 318 K for both the pollutants (RhB and TC) respectively. Modification with metal ions significantly improved the removal efficiency of pure Bi2O3 photocatalyst and followed the trend Co+2/Bi2O3 > Ni+2/Bi2O3 > Cu+2/Bi2O3 > Bi2O3. DFT calculations demonstrate that amongst the doped materials, only Co+2/Bi2O3 is characterized by an indirect band gap; which exhibited efficacious photocatalytic activity. Besides, the highest degradation efficiency was obtained in the case of Co+2/Bi2O3 (2 mol %); being 99.80% for RhB in 30 min and 98.50% for TC in 60 min, respectively. The doped nanostructures lead to higher absorption of visible light and more separation of light-induced charged carriers. Effect of pH of the reaction medium and role of reactive oxygen species was also examined. Finally, a probable mechanism of charge transfer and degradation of the pollutants was also presented.

Visible light-assisted photocatalytic degradation of methylene blue by 1D/2D CdxOy clusters based on metal-organic frameworks without H2O2

Metal-organic frameworks (MOFs) photocatalysts, which contain metal oxo-clusters and organic chromophore linkers, have high visible light absorption utilization, large porosity, specific surface area, effective photogenerated electron and hole separation capabilities. Herein, two types of CdxOy cluster complexes, namely 1D CdxOy cluster Cd-mBDC (mBDC: 1,3-benzenedicarboxylic acid) and 2D CdxOy cluster Cd-2-NH2-mBDC (2-NH2-mBDC: 2-aminoisophthalic acid) were successfully synthesized, and their photocatalytic activity were evaluated by photocatalytic degradation of methylene blue (MB) under visible light without H2O2. The 2D CdxOy cluster of Cd-2-NH2-mBDC can be simplified as a two-dimensional mesh (3.82)(32.82) topology by considering the Cd ions as connected nodes. In addition, conditional experiments showed that the clusters photocatalyst could achieve the best catalytic efficiency under initial dye concentration of 10 mg/L and pH value of 7. Compared with Cd-mBDC, the introduction of amino auxochrome in Cd-2-NH2-mBDC broadened the absorption range and improved the visible light utilization, and the rigid 2D cluster structure facilitated the transfer of photogenerated electrons and enhanced stability. For Cd-2-NH2-mBDC, the photodegradation efficiency of MB could reach 88.44% within 180 min (0.121 min−1) and basically unchanged during five-cycles degradation process. Therefore, Cd-2-NH2-mBDC displays excellent photocatalytic activity and stability for degradation of MB under visible light. Furthermore, the possible mechanism of photocatalytic degradation properties has been also deduced.

Janus-functionalization induced magnetism and improved optoelectronic properties in two-dimension silicene and germanene: insights from first-principles calculations

In this paper, the structural stability, optoelectronic and magnetic properties of silicene and germanene monolayers Janus-functionalized simultaneously with hydrogen and alkali metal atoms (Li and Na) are investigated systematically by using first-principles calculations. The calculated results of the ab initio molecular dynamics simulations and cohesive energies indicate that all functionalized cases have good stability. Meanwhile, the calculated band structures show that all functionalized cases retain the Dirac cone. Particularly, the cases of HSiLi and HGeLi show metallic nature but retain semiconducting characteristics. Besides, the above two cases can present obvious magnetic behavior and their magnetic moments are mainly originated by the p states of Li atom. The metallic property and weak magnetic character can also be found in the case of HGeNa. While the case of HSiNa exhibits the nonmagnetic semiconducting property with a indirect band gap of 0.42 eV calculated by the HSE06 hybrid functional. It is also found that the optical absorption in the visible region of silicene and germanene can be effectively improved by Janus-functionalization. Specifically, a high optical absorption of visible light in an order of 4.5 × 105 cm−1 can be observed in the case of HSiNa. Furthermore, in the visible region, the reflection coefficients of all functionalized cases can also be enhanced. These results demonstrate the feasibility of the Janus-functionalization method to modulate the optoelectronic and magnetic properties of silicene and germanene, expanding their potential applications in the fields of spintronics and optoelectronics.

Synthesis of copper-doped indium zinc sulfide nanosheets for high efficiency photocatalytic hydrogen production

The excessive use of fossil energy has caused a series of environmental problems. Hydrogen is a green energy substitute for fossil energy, and photocatalytic hydrogen production is an effective means of hydrogen production. Indium zinc sulfide catalyst has great application prospect in the field of photocatalysis due to its advantages of high stability and visible light absorption. Based on this, Cu doped indium zinc sulfide nanosheets were prepared in this paper. Compared with pure indium zinc sulfide nanosheets, copper doped indium zinc sulfide nanosheets have better photocatalytic hydrogen production performance. The design and synthesis of photocatalytic hydrogen-producing catalyst has important guiding significance.

α-Fe2O3/CeO2 S-scheme heterojunction photocatalyst for enhanced photocatalytic H2 evolution

High photo-stability and effective charge separation are pivotal for hydrogen production over the photocatalysts through solar energy. Here mesoporous CeO2 nanorods were hydrothermally synthesized using cetyltrimethyl ammonium bromide and tetrapropylammonium hydroxide as the template to construct the novel S-scheme heterojunction α-Fe2O3/CeO2 photocatalyst. The obtained heterojunction Fe2O3/CeO2 photocatalyst exhibited outstanding enhanced H2 evolution under visible illumination. The XRD results indicated that the Fe2O3/CeO2 nanocomposites revealed rhombohedral α-Fe2O3 and cubic CeO2 structures without impurities. TEM images revealed the formation of CeO2 nanorods with 400 nm length and 20 nm width decorated with Fe2O3 NPs (10 nm). The optimized S-scheme Fe2O3/CeO2 nanocomposites displayed a superior photocatalytic H2 evolution rate of 2973.2 µmolg−1h−1, which was promoted 5.43 folds greater than that of CeO2 nanorods (547.05 µmolg−1h−1). The electron transport channels in S-scheme Fe2O3/CeO2 nanocomposites interfacial junctions facilitated the directional migration spatial and separation of photocarriers. The H2 evolution rate over the obtained Fe2O3/CeO2 photocatalyst was significantly promoted due to its synergistic effect, porous architecture, oxygen vacancies, small particle size and high visible light absorption ability. There was no decrease in the H2 evolution rate after five cycles of photocatalytic H2 evolution, which could verify the durability and stability of the Fe2O3/CeO2 nanocomposite. The photoluminescence (PL) and electrophotochemical responses were conducted to determine the charge carriers separation rate and understand the photocatalytic mechanism.

Enhanced pollutant photodegradation over nanoporous titanium-vanadium oxides with improved interfacial interactions

This study addressed the separation problem of colloidal catalytic powder from its solution and pore blockage of traditional metallic oxides by fabricating nanoporous composites of titanium (Ti)-vanadium (V) oxide via magnetron sputtering, electrochemical anodization, and annealing processes. The effect of V-deposited loading on the composite semiconductors was investigated by varying V sputtering power (20–250 W) to correlate their physicochemical properties to the photodegradation performance of methylene blue. The obtained semiconductors revealed circular and elliptical pores (14–23 nm) and formed different metallic and metallic oxide crystalline phases. Within the nanoporous composite layer, V ions substituted Ti4+, leading to Ti3+ formation accompanied by decreased band gap values and higher visible-light absorption. Thus, the band gap of TiO2 was 3.15 eV, while that of Ti-V oxide with the maximum V content (at 250 W) was 2.47 eV. The interfacial separators between clusters in the mentioned composite created traps disrupting the charge carrier movements between crystallites, thereby decreasing the photoactivity. In contrast, the composite prepared with the minimum V content showed approximately 90% degradation efficiency under solar-simulated irradiation resulting from the homogeneous V dispersion and the lower recombination possibility, owing to its p-n heterojunction constituent. The nanoporous photocatalyst layers with their novel synthesis approach and outstanding performance can be applied in other environmental remediation applications.

High-performance visible-light photocatalysis induced by dye-sensitized Ti3+-TiO2 microspheres

Strong visible-light absorption and high surface areas contribute to high-perform semiconductor photocatalysis. This work aims to fabricate self-doped Ti3+-TiO2 microspheres and dye sensitized self-doped Ti3+-TiO2 composites with high surface areas and visible-light absorption via one-pot solvothermal strategy for highly enhanced photocatalytic tetracycline degradation under visible-light irradiation. The experimental results showed that the obtained Ti3+-TiO2 microspheres showed enhanced visible-light capture capacity and a larger surface area of 204.9 m2 g−1. Besides, the obtained Eosin Y/Ti3+-TiO2 composites showed efficient visible-light absorption and highly boosted photocatalytic performance towards tetracycline degradation. The highest rate constant for Eosin Y/Ti3+-TiO2-9% composite reached as high as 0.06657 min−1, approximately 8.09 times that of commercial TiO2, strongly demonstrating the significant roles of dye sensitization. Finally, a reasonable dye-sensitization visible-light photocatalytic mechanism was suggested.

Three-Dimensional Hollow Reduced Graphene Oxide Tube Assembly for Highly Thermally Conductive Phase Change Composites and Efficient Solar-Thermal Energy Conversion.

Due to their extraordinary mechanical strength and electrical and thermal conductivities, graphene fibers and their derivatives have been widely utilized in various functional applications. In this work, we report the synthesis of a three-dimensional (3D) hollow reduced graphene oxide tube assembly (HrGOTA) using the same wet spinning method as graphene fibers. The HrGOTA has high thermal conductivity and displays the unique capability of encapsulating phase change materials for effective solar-thermal energy conversion. The HrGOTA comprises layers of moisture-fused hollow reduced graphene oxide tubes (HrGOTs), whose individual thermal conductivity is up to 578 W m-1 K-1. By impregnating 1-octadecanol into HrGOTs, a 1-octadecanol-filled HrGOT phase change composite (PCC) with a latent heat of 262.5 J g-1 is obtained. This high latent heat results from the interfacial interaction between 1-octadecanol and the reduced graphene oxide tube, as evidenced by the shifts in XRD patterns of 1-octadecanol-filled and 1-octadecanol/multiwalled carbon nanotube-filled HrGOTA samples. In addition, 1 wt % multiwalled carbon nanotubes are added to the PCC to enhance visible light absorption. Because of their high thermal conductivity and visible light absorption rates, these new PCCs display high solar-thermal energy conversion and storage efficiencies of up to 81.7%, commensurate with state-of-the-art carbon-based PCCs but with significantly lower carbon weight percentages.

Carbon and nitrogen co-doped In2O3 porous nanosheets with oxygen vacancies for remarkable photocatalytic CO2 conversion

Photocatalytic CO2 reduction to sustainable products by utilizing solar energy has great prospects for development. However, most of the conventional catalysts have the disadvantages of inefficient, low visible light absorption, and poor product selectivity. For this reason, in this study, carbon and nitrogen co-doped In2O3 (C,N-In2O3) porous nanosheets with oxygen vacancies have been successfully prepared by pyrolyzing the as-prepared carbon-rich InOOH (C-InOOH) nanosheets precursor in an ammonia-helium mixture gas. The derived C,N-In2O3 photocatalyst possesses a mesoporous structure, large surface area, accelerated charge transfer and separation, and high visible-light absorption ability. The carbon and nitrogen co-doping produced proper surface defects (oxygen vacancies), which can facilitate CO2 adsorption and inhibit photogenerated charge recombination. As expected, an efficient CO2 photoreduction is achieved over the C,N-In2O3 sample with a CO production rate of 152 μmol h−1 g−1 and 80% selectivity together with an excellent stability. This study provided an efficient C,N co-doping strategy for fabricating high-active and stable photocatalysts, which could be applied to the conversion and utilization of solar energy in the future.

Durable self-cleaning PVDF coating with photocatalysis and superhydrophobic property based on hierarchical coral-like 2D g-C3N4/1D TiO2 hybrid

The low-availability of visible light and poor durability of photocatalytic superhydrophobic coatings are two major challenges for practical applications. In this paper, a heterojunction structure was formed by using the force assembly between two-dimensional graphitic carbon nitride (2D g-C3N4） and one-dimensional titanium dioxide nanorods (1D TNr）, and then the surface was modified by 1 H, 1 H, 2 H, 2 H-perfluorodecyltriethoxysilane (PFDTS). MGT (Modified g-C3N4/TNr Heterojunction Composite) heterojunction was uniformly dispersed in the PVDF/PTFE mixture to form a coating that can be easily applied for spraying. MGT has superior charge carrier separation and high visible light absorption, which endows the MGT/PVDF/PTFE coating with exceptional performance in visible photocatalytic degradation of pollutants. The micro-nano 3D structure with low surface energy constructed by MGT and PVDF/PTFE contributes to the superhydrophobicity of the coating. The outstanding visible light photocatalytic and superhydrophobicity provide the coating with highly efficient self-cleaning performance. Impressively, the coating presents remarkable abrasion resistance and resistance to harsh environments such as acids, alkalis, salts, and UV irradiation thanks to the firm adhesion of MGT, the excellent solvent, and oxidation resistance of PVDF/PTFE. Therefore, this durable and highly efficient photocatalytic superhydrophobic coating is expected to be produced industrially and applied on a large scale.

An organic semiconductor obtained with a low-temperature process for light-addressable potentiometric sensors

In this study, the first trial of donor and acceptor bulk heterojunctions (BHJs) is proposed for light-addressable potentiometric sensors (LAPSs) due to organic conjugated molecules with the advantages of energy level/band gap modification and high absorption of visible light. The benzodithiophene-based polymer PTB7-Th and fullerene PC71BM are selected for integration with an Al2O3 sensing membrane using atomic layer deposition at temperatures lower than 100 ℃ for pH sensing LAPS. In the stability performance, the hysteresis width of the best condition with a mixing weight ratio of PC71BM to PTB7-Th of 1.5 is 4.4 mV, which is inferior to that of the conventional inorganic semiconductor-based LAPSs. By means of an additional spin-coated zinc oxide (ZnO) layer, the signal-to-noise ratio of the photocurrent of this fabricated LAPS can be maintained at 3.2 after 170 min of measurement with an acceptable sensitivity, linearity, drift coefficient and hysteresis of 50.2 mV/pH, 99.9%, − 3.1 mV/h and 1.4 mV, respectively. With the proper adjustment of illumination with low power and large spots, chemical imaging with a scanning step of 25 µm can be conducted to indicate the feasibility of this low-temperature process developed for spin-coated organic semiconductor-based LAPSs.

Cold and hot-casting to regulate morphology and charge carrier dynamics of CsBi3I10 towards efficient and stable thin-film solar cells

Inorganic semiconductor CsBi3I10 (CBI) emerges as one of the most promising candidates for lead-free perovskite solar cells (PSCs) due to its low toxicity, high visible light absorption and excellent humidity...