Higher Photocurrent Intensity Research Articles

Enhancing methane production from corn straw via illumination-assisted Fe3O4/g-C3N4 nanocomposite in anaerobic digestion

This study proposes a novel anaerobic digestion (AD) strategy combining recyclable photoactivated nanomaterials with illumination to enhance electronic transfer for anaerobic microorganisms. Results showed that 7000 Lux illumination increased methane production yield and rate. Incorporating Fe3O4 into graphite carbon nitride (g-C3N4) created a recyclable Fe3O4/g-C3N4 (FG) nanocomposite with improved light absorption, conductivity, redox properties, and methane promotion. The highest methane yield from corn straw was achieved with 7000 Lux and 1.5 g/L FG nanocomposite, 22.6% higher than the dark control. The AD system exhibited increased adenosine triphosphate content, improved redox performance, reduced electron transfer resistance, and higher photocurrent intensity. These improvements bolstered the microorganisms and key genes involved in hydrolysis and acidification, which in turn optimized the acetoclastic pathway. Furthermore, this strategy promoted microorganisms associated with direct interspecies electron transfer, fostering a favorable environment for methanogenic activities, paving the way for future anaerobic reactor developments.

Integrating CdIn2S4 semiconductors with S-vacancy MoS2 nanosheets to fabricate a multi-channel aptasensing chip for photoelectrochemical detection of multiple mycotoxins

BackgroundThe importance of multi-target simultaneous detection lies in its ability to significantly boost detection efficiency, making it invaluable for rapid and cost-effective testing. Photoelectrochemical (PEC) sensors have emerged as promising candidates for detecting harmful substances and biomarkers, attributable to their unparalleled sensitivity, minimal background signal, cost-effectiveness, equipment simplicity, and outstanding repeatability. However, designing an effective multi-target detection strategy remains a challenging task in the PEC sensing field. Consequently, there is a pressing need to address the development of PEC sensors capable of simultaneously detecting multiple targets. ResultsCdIn2S4/V–MoS2 heterojunctions were successfully prepared via a hydrothermal method. These heterojunctions exhibited a high photocurrent intensity, representing a 1.53-fold enhancement compared to CdIn2S4 alone. Next, we designed a multi-channel aptasensing chip using ITO as the substrate. Three working electrodes were created via laser etching and subsequently modified with CdIn2S4/V–MoS2 heterojunctions. Thiolated aptamers were then self-assembled onto the CdIn2S4/V–MoS2 heterojunctions via covalent bonds, serving as recognition tool. By empolying the CdIn2S4/V–MoS2 heterojunctions as the sensing platform and aptamers as recognition tool, we successfully developed a disposable aptasensing chip for the simultaneous PEC detection of three typical mycotoxins (aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN)). This aptasensing chip exhibited wide detection range for AFB1 (0.05–50 ng/mL), OTA (0.05–500 ng/mL), and ZEN (0.1–250 ng/mL). Furthermore, it demonstrated ultra-low detection limits of 0.017 ng/mL for AFB1, 0.016 ng/mL for OTA, and 0.033 ng/mL for ZEN. Significance and noveltyThe aptasensing chip stands out for its cost-effectiveness, simplicity of fabrication, and multi-channel capabilities. The versatility and practicality enable it to serve as a powerful platform for designing multi-channel PEC aptasensors. With its ability to detect multiple targets with high sensitivity and specificity, the aptasensing chip holds immense potential for applications across diverse fields, such as environmental monitoring, clinical diagnostics, and food safety monitoring, where multi-target detection is crucial.

Visible-light-driven photocatalytic degradation of ibuprofen by Cu-doped tubular C3N4: Mechanisms, degradation pathway and DFT calculation

The copper-modified tubular carbon nitride (CTCN) with higher specific surface area and pore volume was prepared by a simple in-situ hydrolysis and self-assembly. Increased ∼4.7-fold and ∼2.3-fold degradation rate for a representative refractory water pollutant (Ibuprofen, IBP) were achieved with low-energy light source (LED, 420 ± 10 nm), as compared to graphitic carbon nitride (GCN) and tubular carbon nitride (TCN), respectively. The high efficiency of IBP removal was supported by narrow band gap (2.15 eV), high photocurrent intensity (1.10 μA/cm2) and the high surface -OH group (14.75 μg/cm3) of CTCN. According to analysis of the various reactive species in the degradation, the superoxide radical (•O2−) played a dominant role, followed by •OH and h+, responsible for IBP degradation. Furthermore, Fukui functions were employed to predict the active sites of IBP, and combined with the HPLC-MS/MS results, possible mechanisms and pathways for photocatalytic degradation were indicated. This study will lay an important scientific foundation and a possible new approach for the treatment of emerging aromatic organic pollutants in visible-light-driven heterogeneous catalytic oxidation environment.

A mixed valence decanuclear cerium-oxo cluster CeIII4CeIV6 for efficient photocurrent response

Cerium-oxo clusters with mixed valence exhibit distinctive redox properties due to cerium ions switch between +3/+4 valence states. However, the design and synthesis of these clusters present formidable challenges, resulting in limited availability of such species, often necessitating the use of both CeIII and CeIV reactants. Herein, we successfully obtained a mixed valence cerium-oxo cluster CeIII4CeIV6(µ3-O)4(µ4-O)4(acac)14(CH3O)6(CH3OH)2 (CeIII4CeIV6, Hacac = acetylacetone) through low-temperature crystallization only using the trivalent cerium salt. The coexistence as well as the distribution of Ce ions in different valence states have been determined from a multifaceted analysis. In addition, the stability of the synthesized cluster was confirmed by the HRESI-MS study through redissolution of the single crystal sample in fresh methanol. Importantly, Importantly, this study reveals the mechanism for the generation of +4 valence state. Under alkaline conditions, the presence of trace oxygen and the involvement of acetylacetone ligand facilitated the partial oxidation of CeIII to CeIV. The cluster CeIII4CeIV6 has strong ultraviolet absorption and long visible light absorption. As the electrode precursor, CeIII4CeIV6 showed clear photocurrent response and high photocurrent intensity due to CeIII/CeIV redox reaction.

Ultra-sensitive photoelectrochemical biosensor for determination of African swine fever virus based on surface plasmon resonance

Sensitive and specific detection of African swine fever virus (ASFV) is crucial for agricultural production and economic development due to the mortality and infectivity. In this study, a bismuth induced enhanced photoelectrochemical (PEC) biosensor based on in-situ loop mediated isothermal amplification (LAMP) was constructed using deposited bismuth nanoparticles loaded bismuth oxycarbonate (Bi/(BiO)2CO3) as photoactive material, using primers designed according to LAMP as recognition elements, and using in-situ LAMP to achieve nucleic acid amplification of target genes. As the Bi induced surface plasmon resonance (SPR) effect, enhanced light captures and effective electron hole separation, it could effectively enhance the photoelectric activity, so the prepared Bi/(BiO)2CO3 nanohybrid had higher photocurrent intensity and good stability. The constructed PEC biosensor has realized the detection of ASFV in real samples with good sensitivity, specificity and repeatability. In the range from 1.0 × 10−13 to 1.0 × 10−7 g/L, the photoelectric current decreased with the increase of the concentration of ASFV, and the detection limit was 3.0 × 10−14 g/L (about 0.048 copies/μL). Combining the advantages of LAMP with the excellent performance of PEC, it provides a simple, economical and efficient method for nucleic acid diagnosis, and also provides a new idea for biosensor detection.

Boosting photocatalytic hydrogen production based on amino acid derived Zn-MOF/CdS composite photocatalysts

The utilization of solar energy to decompose water and produce hydrogen is one of the important strategies to solve the problems of ecological environment and energy crisis. Herein, a series of CdS-modified Metal-Organic Frameworks (MOFs) composites Zn(LFor)-MOF/CdS were successfully prepared through the reaction of N-(4-pyridine-methyl)-l-valine·HCOONa (NaLFor), Zn acetates, and CdS nanoparticles. The composite Zn(LFor)-MOF/CdS exhibit a very high photocatalytic performance for hydrogen production from water cracking under visible light irradiation, which is superior to the pristine MOF and cadmium sulfide materials. The hydrogen production based on different proportions of Zn(LFor)-MOF/CdS materials were investigated, and the prepared Zn(LFor)-MOF/CdS (4:1) material showed excellent hydrogen evolution performance with the hydrogen yield reaching 267.6 μmol/h. Zn(LFor)-MOF/CdS (4:1) has a high photocurrent intensity, which can effectively inhibit the photoelectron-hole recombination, improve the electron-hole transport ability at the interface, accelerate the electron migration, which makes this material a high hydrogen production photocatalytic activity.

Unveiling Hierarchical Dendritic Co3O4–SnO2 Heterostructure for Efficient Water Purification

The construction of a desirable, environmentally friendly, and cost-effective nanoheterostructure photoanode to treat refractory organics is critical and challenging. Herein, we unveiled a hierarchical dendritic Co3O4-SnO2 heterostructure via a sequential hydrothermal process. The time of the secondary hydrothermal process can control the size of the ultrathin SnO2 nanosheets on the basis of the Ostwald solidification mass conservation principle. Ti/Co3O4-SnO2-168h with critical growth size demonstrated a photoelectrocatalysis degradation rate of ∼93.3% for a high dye concentrate of 90 mg/L with acceptable long-term cyclability and durability over reported Co3O4-based electrodes because of the large electrochemically active area, low charge transfer resistance, and high photocurrent intensity. To gain insight into the photoelectric synergy, we proposed a type-II heterojunction between Co3O4 and SnO2, which prevents photogenerated carriers' recombination and improves the generation of dominant active species •O2-, 1O2, and h+. This work uncovered the Ti/Co3O4-SnO2-168 as a promising catalyst and provided a simple and inexpensive assembly strategy to obtain binary integrated nanohybrids with targeted functionalities.

A facile synthesis of visible light driven Ni3V2O8 nano-cube/BiVO4 nanorod composite photocatalyst with enhanced photocatalytic activity towards degradation of acid orange 7

Photocatalysis is one of the promising method to degrade harmful organic pollutants under visible light exposure. In this work, a novel Ni3V2O8/BiVO4 nanocomposite has been prepared by one-pot hydrothermal method, and investigated through X-ray diffraction, FT-IR, UV–visible diffuse reflectance spectroscopy, scanning and transmission electron microscopy and photoluminescence techniques. Subsequently, the photocatalytic performance of Ni3V2O8/BiVO4 nanocomposite has been examined by degrading AO7 under visible light illumination. The photocatalytic efficiency of the optimized 1:2 ratio of Ni3V2O8/BiVO4 nanocomposite photocatalyst is found to be 87% with a rate constant value of 0.03387 min−1 which are higher than those of other prepared photocatalysts. This nanocomposite exhibits excellent stability even after 3 three cycles, and shows 1.135- and 1.17-times higher photocurrent intensity than pure BiVO4 and Ni3V2O8 respectively. The mechanism for the degradation of AO7 over Ni3V2O8/BiVO4 nanocomposite photocatalyst has been proposed.

A novel photoelectrochemical immunosensor based on TiO2@Bi2WO6 hollow microspheres and Ag2S for sensitive detection of SARS-COV-2 nucleocapsid protein

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) is a cluster of β coronaviruses. The 2019 coronavirus disease (COVID-19) caused by SARS-COV-2 is emerging as a global pandemic. Thus, early diagnosis of SARS-COV-2 is essential to prevent severe outbreaks of the disease. In this experiment, a novel label-free photoelectrochemical (PEC) immunosensor was obtained based on silver sulfide (Ag2S) sensitized titanium dioxide@bismuth tungstate (TiO2@Bi2WO6) nanocomposite for quantitative detection of SARS-COV-2 nucleocapsid protein. The constructed TiO2@Bi2WO6 hollow microspheres had large specific surface area and could produce high photocurrent intensity under visible light illumination. Ag2S was in-situ grown on the surface of thioglycolic acid (TGA) modified TiO2@Bi2WO6. In particular, TiO2@Bi2WO6 and Ag2S formed a good energy level match, which could effectively enhance the photocurrent conversion efficiency and strength the photocurrent response. Ascorbic acid (AA) acted as an effective electron donor to effectively eliminate photogenerated holes. Under optimal experimental conditions, the constructed immunosensor presented a supersensitive response to SARS-COV-2 nucleocapsid protein, with a desirable linear relationship ranged from 0.001 to 50 ng/mL for nucleocapsid protein and a lower detection limit of 0.38 pg/mL. The fabricated sensor exhibited a wide linear range, excellent selectivity, specificity and stability, which provided a valuable referential idea for the detection of SARS-COV-2.

Fabrication and characterization of photoelectrode B–Co/TiO2 nanotubes for effective photoelectrochemical degradation of rhodamine B

The TiO2 nanotubes (TNT), B/TiO2 nanotubes (B/TNT), Co/TiO2 nanotubes (Co/TNT), and B–Co/TiO2 nanotubes (B–Co/TNT), which were produced by the anodization technique, were used as photoelectrodes for the photoelectrochemical (PEC) degradation of Rhodamine B (RhB). The produced electrodes were characterized by SEM, XRD, UV–Visible Spectrophotometer, and XPS analysis. The responses of the photocurrent density of NTs were used to determine the PEC performances. The linear sweep voltammetry results showed that the photocurrent densities of TNT, B/TNT, Co/TNT, and B–Co/TNT reached 0.31, 0.75, 1.12, and 2.1 mA/cm2 at 0.6 V. The photocurrent densities of B/TNT, Co/TNT, and B–Co/TNT were about 2.42, 3.61, and 6.77 times higher than the photocurrent density of TNT, respectively. The stability study for B–Co/TNT with the highest photocurrent intensity was carried out under 10 h of irradiation and there was no significant change in the photocurrent intensity NTs. The evaluation of electrocatalytic, photocatalytic, and photoelectrocatalytic performances of B–Co/TNTs photoelectrode was performed on the degradation of RhB, and the dye degradation of 14.3%, 41.8%, and 95.5% was obtained, respectively. To determine the effect of doping on TNTs on the PEC activity, the degradation experiments of RhB on the TNT, B/TNT, Co/TNT, and B–Co/TNT photoelectrodes were investigated and the rates of dye degradation of 46.8%, 63.4%, 73%, and 95.5% were obtained, respectively. This study demonstrated that doping B, Co, and B–Co ions into TNTs significantly increased the performance of PEC degradation of RhB.

Fabrication and characterization of carbon quantum dots decorated hollow porous graphitic carbon nitride through polyaniline for photocatalysis

Metal-free photocatalysts are widely used to decontaminate aqueous solutions by eliminating toxic and non-biodegradable compounds. It is desirable to develop a photocatalyst with high charge separation and migration efficiency. The addition of carbon quantum dots (CQDs) to graphitic carbon nitride with polyaniline (PANI) can improve its light absorption abilities and reduce the recombination of holes and electrons. In this study, a novel CQDs decorated on PANI with hollow porous graphitic carbon nitride (CN) was fabricated via an in situ polymerization followed by an ultra-sonication. The optimal CQDs–loaded CN-PANI nanocomposite exhibited the high visible light absorption with a high specific surface area. Furthermore, better photocatalytic degradation of ciprofloxacin (CIP) was achieved under the visible light. The improved photocatalytic activity of CN-PANI-CQDs (5.0%) can be attributed to its higher charge separation, and destruction of recombination rate through the heterojunction of excited electrons among CN, PANI, and CQDs. This effect was further confirmed by high photocurrent intensity, low photoluminescence emission, and electrical resistance. In addition, different parameters including catalyst weight, initial CIP concentration, and interfering effect of anions during CIP removal were investigated. The main active species in the degradation of CIP were identified to h+, •OH, and •O2− through the scavenger test. The high reusability and stability of the photocatalyst composite were also verified. The degradation intermediates and reaction pathways were identified. Furthermore, the effectiveness of the photocatalyst was evaluated using different toxic pollutants including imidacloprid, tetracycline, phenol, and rhodamine B under similar conditions. The CQDs–decorated CN-PANI was proved as a promising material for efficient photodegradation of toxic pollutants in water.

Mass-produced flexible Br doped PEDOT modified carbon paper electrodes for constructing mercury ion photoelectrochemical sensor

Mercury (Hg) is a kind of the most common heavy metals with high toxicity in nature, existing in water, soil, and even food. Hence, it is of great importance to develop a simple, effective way to detect Hg2+. Flexible sensing has attracted extensive attention in recent years, which can be flexibly applied in various detection environments. Poly(3,4-ethylenedioxythiophene) (PEDOT) with conjugation structure which can accelerate the transfer of electrons and inhibit the recombination of carriers is favorable to the photoelectrochemical (PEC) process. Here, Br doped PEDOT modified carbon paper with narrower bandgap was firstly fabricated through situ thermal polymerization which exhibited high photocurrent intensity under visible-light irradiation. The success synthesis of PEDOT was confirmed by SEM, XPS, FT-IR and Raman spectrum. Meanwhile, the as-prepared electrode can be mass produced with good reproducibility. Based on excellent performance of as-prepared electrode of Br doped PEDOT/carbon paper, we constructed a PEC sensing platform for Hg2+ detection with the detection limit of 0.3 nM and linear range from 1 nM to 450 nM. In addition, the PEC sensor exhibited speedy response, outstanding stability, excellent selectivity, wide linear range, and was used for determination of Hg2+ in river water samples with recover range of 97.7–104.5 % and RSD of 2.8–4.7 %.

Synthesis of functional conjugated microporous polymer/TiO2 nanocomposites and the mechanism of the photocatalytic degradation of organic pollutants

We successfully synthesize six kinds of functional conjugated microporous polymer (CMP) containing amino, hydroxyl, carboxyl and ester groups by a Sonogashira–Hagihara coupling reaction. These CMPs exhibit type-I nitrogen gas sorption isotherms, and their pore widths are approximately 1.28–1.86 nm with a relatively narrow pore size distribution that is attributed to microporous structures. By blending CMPs with TiO2 under solvothermal conditions, TiO2 is uniformly coated onto the surfaces of the CMPs, and CMP/TiO2 nanocomposites are synthesized successfully. The novel nanocomposites show excellent photocatalytic properties for the degradation of organic pollutants, such as methylene blue, ciprofloxacin and tetracycline, under visible light. The degradation rate of organic pollutants is higher than 96.8%, and after 5 recycling cycles, the degradation efficiency is still more than 93%. The effects of the different functional groups of CMPs on the photocatalytic properties are discussed for the first time. CMP/TiO2 with carboxyl groups show the smallest band gap, highest photocurrent intensity and lowest resistance compared to those of nanocomposites with amino, hydroxyl and ester groups. This result may be caused by the high electronegativity of carboxyl groups, which enhances the charge transfer rate. The photocatalytic mechanism of the CMP/TiO2 nanocomposites is investigated, and the superoxide anion (·O2−) is the main active species in the photocatalytic degradation process.

Facile ball-milling synthesis of CeO2/g-C3N4 Z-scheme heterojunction for synergistic adsorption and photodegradation of methylene blue: Characteristics, kinetics, models, and mechanisms

• The solvent-free ball-milling method obtains Z-scheme CeO 2 /g-C 3 N 4 heterojunction. • CeO 2 /g-C 3 N 4 thermodynamically has stronger redox potential and active radicals. • 70% CeO 2 /g-C 3 N 4 exhibited the best removal efficiency for MB photodegradation. • Synergy between adsorption and photodegradation of MB by CeO 2 /g-C 3 N 4 was identified. As a green solvent-free process, ball milling has attracted considerable attention in fabricating nanocomposites. Herein, we synthesized novel Z-scheme heterojunction CeO 2 /g-C 3 N 4 nanocomposites by simply direct ball milling CeO 2 and g-C 3 N 4 at three different mass ratios (3:7, 7:3, and 9:1). In comparison to individual CeO 2 and g-C 3 N 4 , the ball-milled nanocomposites showed stronger UV light response, higher charge carrier separation efficiency, greater photodegradation potential, higher photocurrent intensity, and faster electron transfer, indicating much better photocatalytic activity. When used as photocatalysts to remove methylene blue (MB) under UV light irradiation, 70% CeO 2 /g-C 3 N 4 exhibited the highest removal rate (90.1%), much better than that of CeO 2 (6.2%) or g-C 3 N 4 (45.7%). The synergistic interact between adsorption and photodegradation of the CeO 2 /g-C 3 N 4 nanocomposites was simulated by kinetic models, and a strong positive correlation (r = 0.834 and r s = 0.777) between adsorption and photocatalysis was identified. The results indicate that adsorption can promote photodegradation by accelerating the kinetics, while photodegradation can regenerate adsorption sites. This work provides not only a facile synthesis of Z-scheme heterojunction photocatalysts but also a novel perspective for better understanding the synergy between adsorption and photocatalysis.

Improved photocatalytic H2 evolution performance of mesoporous graphitic carbon nitride with cyano-group

In this paper, two modification strategies were introduced in g-C3N4 system to improve its photocatalytic activity. In detail, mesoporous g-C3N4 with cyano-group was successfully synthesized. Its chemical structure and states, specific surface area, optical absorption, photo-electrochemical properties and photocatalytic ability for hydrogen evolution were characterized. It was indicated that mesoporous g-C3N4 with cyano-group photocatalyst exhibited better charge separation rate, and the higher photocurrent intensity, For hydrogen evolution, it achieved the higher hydrogen evolution rate of 4531 μmol·h−1 g−1, which was 3 folds that of mesoporous g-C3N4 and 13 folds that of bulk g-C3N4, and kept excellent stability. Obviously, current work shed light for developing high efficient photocatalysts by combining multiple modification.

Boosting photoelectrochemical and photocatalytic performances of electronspun WO3 nanofibers by combining with biphase-Ag2WO4

A novel biphase silver tungstate (Ag2WO4)/tungstate oxide (WO3) photocatalyst was synthesized through electrospinning process combined with a facile solid chemical reaction. The X-ray diffraction patterns, energy dispersive spectroscopy and Fourier transform infrared spectroscopy demonstrated that the photocatalyst is composed of monoclinic WO3, β-Ag2WO4 and γ-Ag2WO4. The Ag2WO4/WO3 can completely degrade the rhodamine B (RhB) within 20 min under 300 W xenon lamp. The first-order kinetics constant k of Ag2WO4/WO3 is 26.3 times of WO3. The recycling photocatalytic tests proclaimed that the Ag2WO4/WO3 is relatively stable. The composites possess smaller impedance and higher photocurrent intensity, which displayed the promoted photoelectrochemical activities. The broadened light harvesting and accelerated photogenerated charge carrier migration account well for the enhanced photocatalytic performance of the composite. The direct Z-scheme photocatalytic mechanism should be responsible for the boosted photocatalytic performances of biphase Ag2WO4/WO3. This work gave new insights into the design and construction of WO3-based direct Z-scheme photocatalysts.

Plasmonic p-n heterojunction of Ag/Ag2S/Ag2MoO4 with enhanced Vis-NIR photocatalytic activity for purifying wastewater

The sensitivity of photocatalysts to visible (Vis) and near infrared (NIR) light has been attracting considerable attention owing to its high utilization efficiency of solar energy. Herein, we have successfully constructed Ag/Ag2S/Ag2MoO4p-n heterojunctions by hydrothermal method, which displays obvious surface plasmon resonance (SPR) and wide photoabsorption range from Vis to NIR light (400–900 nm). Ag/Ag2S/Ag2MoO4 exhibits the weakest photoluminescence (PL) spectroscopy and highest photocurrent intensity, indicating greater separation efficiency of photogenerated electron-hole pairs compared with Ag/Ag2S and Ag/Ag2MoO4. Under the visible light irradiation, Ag/Ag2S/Ag2MoO4 can remove 99% RhB, 100% MB, 83% TC and 77% Cr(VI), higher than that of Ag/Ag2S or Ag/Ag2MoO4. Importantly, with 808 nm laser as light source, Ag/Ag2S/Ag2MoO4 shows excellent NIR-driven photocatalytic activity (62% RhB, 58% MB, 52% TC and 50% Cr(VI)), compared to Ag/Ag2S or Ag/Ag2MoO4. The excellent photocatalytic performance of Ag/Ag2S/Ag2MoO4 under Vis or NIR light roots from high separation efficiency of photogenerated carriers derived from the construction of Ag/Ag2S/Ag2MoO4p-n heterojunctions. Additionally, Ag/Ag2S/Ag2MoO4 can be easily recycled with high stability. Therefore, Ag/Ag2S/Ag2MoO4 can be employed as efficient and recyclable Vis-NIR-driven photocatalyst for the purification of wastewater.

Pt Nanowire-Anchored Dodecahedral Ag3PO4{110} Constructed for Significant Enhancement of Photocatalytic Activity and Anti-Photocorrosion Properties: Spatial Separation of Charge Carriers and PhotogeneratedElectron Utilization

Pt nanowire-anchored dodecahedral Ag3PO4{110} was constructed for organics photodegradation. SEM and TEM images confirmed that the Pt nanowires were grafted on dodecahedral Ag3PO4, which was entirely bounded by {110} facets. All the X-ray diffraction peaks of the samples were indexed to the body-centered cubic phase of Ag3PO4, indicating that Pt nanowire-anchored dodecahedral Ag3PO4 well maintained the original crystal structure. The rhombic dodecahedral Ag3PO4 entirely bounded by {110} facets achieved high photocatalytic activity. Due to the formation of a Schottky barrier, the Pt nanowires improved the separation of the charge carriers of Ag3PO4. Furthermore, they provided a fast expressway to transfer the photogenerated electrons and prolonged the lifetime of the charge carriers via long-distance transport, resulting in the accumulation of holes on Ag3PO4 for organics degradation. More importantly, the Pt nanowires improved the reduction potential of the photogenerated electrons for O2 reduction to ·O2−, which enhanced the photocatalytic activity and anti-photocorrosion properties of Ag3PO4. We found that 99.5% of Rhodamine B (RhB) could be removed over 0.5ωt% Pt nanowire-anchored dodecahedral Ag3PO4 within 10 min. Even after 10 cycles, the photocatalytic activity was still high. photoluminescence (PL), time-resolved photoluminescence (TRPL), UV–vis diffuse reflectance spectra (UV–visDRS), and photoelectrochemical analysis showed that Pt nanowire-anchored dodecahedral Ag3PO4 exhibited lower bandgap, higher photocurrent intensity, better electronic conductivity, and longer charge carriers lifetime than other types of Ag3PO4 crystals. Radical trapping experiments and electron paramagnetic resonance (EPR) analysis demonstrated that the holes were the main active species for organics photodegradation.

Enhanced Removal of Toxic Cr(VI) in Wastewater by Synthetic TiO2/g-C3N4 Microspheres/rGO Photocatalyst under Irradiation of Visible Light

Herein, the cost-effective photocatalyst of TiO2/g-C3N4 microspheres/reduced graphene oxide (T-CNS-G) was synthesized through a simplified two-pot hydrothermal procedure and its structure and characteristics were researched by various characterizations. The as-prepared T-CNS-G nanohybirds exhibited obviously enhanced photocatalytic activities (about 90% after 4 h) for Cr(VI) removal and good cycle stability (five cycles), which was irradiated by visible light. The increased photocatalytic activity of T-CNS-G photocatalysts is the result of the positive synergy of TiO2 nanoparticle, g-C3N4 microspheres, and rGO nanosheets. The synergy made the composite catalyst have a larger specific surface area, stronger visible light absorption capacity, lower fluorescence intensity, and higher photocurrent intensity, thereby increasing the active site of the catalysts and the mobility of photoinduced carriers. In addition, the possible photocatalytic reaction mechanism for a high-efficiency removal of Cr(VI) was propo...

Nanodiamond enhanced ZnO nanowire based UV photodetector with a high photoresponse performance

In this work, a nanodiamond enhanced ZnO nanowire based UV photodetector was fabricated via an inexpensive spin-coating method, which exhibits a high photocurrent responsibility of 0.59A/W and a high photocurrent intensity of 819.75 μA/cm2. Meanwhile, the reason of outstanding responsibility was systemically investigated by adjusting the interim morphologies and interface of synthesized nanodiamond/ZnO. This work represents a simple and efficient route to fabricate the larger scale UV photodetector with a high photoresponse performance.