Outstanding Photocatalytic Performance Research Articles

One-step fabrication of Bi2MoO6 nanowires-g-C3N4 composites for outstanding photocatalytic performance in cyclohexane oxidation

Selective oxidation of cyclohexane into cyclohexanone (K) and cyclohexanol (A) stands as a pivotal process in industrial chemistry. However, the challenges associated with activating the C-H bond and the vulnerability of KA oil to over-oxidation detract from the economic significance of this reaction. This study focuses on the preparation of a bismuth molybdate ultrathin nanowires-carbon nitride (Bi2MoO6-g-C3N4) heterojunction through a one-step hydrothermal approach for significantly improving the photocatalytic oxidation of cyclohexane. Bi2MoO6 ultrafine nanowires with the diameter of 6 nm were adhered tightly on the surface of g-C3N4 nanosheets with the assistance of oleyl amine. The type II heterojunction of Bi2MoO6-g-C3N4 composite facilitated a more efficient separation of charges and boosted the photocatalytic performance in the cyclohexane oxidation. The Bi2MoO6-g-C3N4 composite demonstrated outstanding photocatalytic performance with a 10.66 % conversion rate of cyclohexane, surpassing the individual efficiencies of Bi2MoO6 and g-C3N4 by 1.9 and 2.2 times, respectively. Moreover, it demonstrated an outstanding KA oil selectivity of 99.32 %, showcasing exceptional levels of both conversion and selectivity simultaneously. Through the utilization of photoelectrochemical analysis, research on band structures, experiments on radical trapping and monitoring, we have extensively investigated the mechanism of photocatalysis. The type II charge transfer in Bi2MoO6-g-C3N4 heterojunction restricted the redox capacity of electrons in the conduction band and holes in the valence band, effectively curbing over-oxidation reactions of KA oil, thus achieving remarkable KA oil selectivity. It offers a valuable insight into the creation of heterojunctions to boost the efficiency of photocatalytic oxidation of cyclohexane, showing promise for advancing the field of photocatalysis.

Boosted Photocatalytic CO2 Conversion of a Cs2AgBiBr6@Co3O4 Composite with High Activity and Selectivity under Low-Concentration CO2 and Natural Sunlight

To explore high-efficiency photocatalysts that can operate under low-concentration CO2 and natural light conditions remains a significant challenge in the field of photocatalysis. Here, we have constructed lead-free Cs2AgBiBr6@Co3O4 (CABB@Co3O4) composites with compact heterogenous interfaces, enhanced CO2 adsorption capability and excellent photoelectronic characteristics. The optimal CABB@Co3O4 heterojunction exhibits nearly 100% selectivity for visible-light-driven CO2 to CO conversion with the high catalytic efficiency and stability in high-purity and diluted CO2. Importantly, the CABB@Co3O4 photocatalyst is one of a few examples to drive photocatalytic CO2 reduction under the 5v% CO2 and natural sunlight, exhibiting a linear relationship between CO evolution rate and light intensity. The outstanding photocatalytic performance mainly originates from the suppressed carrier recombination and the decreased energy barrier for the formation of the key *COOH intermediate. This work provides prospective guidance for designing efficient photocatalysts toward CO2 conversion under the actual environmental conditions.

Ni-Metalized Covalent Organic Cage as a Photocatalyst for Selective Photoreduction of CO2 to CO.

Metal complex-based photocatalysts are promising for CO2 reduction. Their catalytic performances greatly rely on the synergy of ligands and metal ions. Here, we demonstrate an assembly of covalent organic cage (COC) and metal ions for photocatalytic CO2 reduction. The coordinated metal serves as catalytically active site for CO2 reduction, while the cage not only chelates the metal site, but also enhances the local concentration of CO2 around metal site, and decreases the key intermediate reaction energy barrier, thereby promoting the CO2 reduction reaction kinetically and thermodynamically. Accordingly, a Ni metalized COC exhibited outstanding photocatalytic performance in CO2-to-CO conversion under visible light irradiation. This study highlights the feasibility and advantage of organic cages for the construction of photocatalysts for artificial photosynthesis.

Facile construction of a novel dual Z-scheme mixed phases BiFeO3 heterojunction: For peroxymonosulfate activation toward efficient photodegradation of 4-nitrophenol and mechanistic insights

This study proposes a novel approach for preparing bismuth ferrite (BiFeO3, BFO) with controlled crystal phase purity and morphology via a one-pot hydrothermal process using specific mineralizers (NaOH or KOH). The effects of these mineralizers on the crystal purity and photocatalytic efficiency of the catalyst were investigated. The XRD results revealed that KOH produced pure BFO, whereas NaOH yielded mixed-phase BFO (m-BFO) with secondary phases, including Bi2O3 and Bi2Fe4O9. SEM analysis revealed that m-BFO exhibited a flake-like structure assembled into cubes, whereas pure BFO consisted of irregularly shaped agglomerated nanoparticles. The photocatalytic efficiency of the two catalysts was evaluated for the degradation of 4-nitrophenol (4-NP). The results showed that m-BFO exhibited outstanding photocatalytic degradation performance (92%) for 4-NP compared with pure BFO (22%). The enhanced photocatalytic efficiency of m-BFO was attributed to the construction of a dual-heterojunction Z-scheme within its structure and the presence of abundant surface oxygen vacancies. This study provides valuable insights into the synthesis of efficient dual-heterojunction Z-scheme photocatalysts via one-pot hydrothermal synthesis.

Photocatalytic degradation of norfloxacin antibiotic by a novel Cu-ZnO/BiOI/Bi2WO6 double Z-type heterojunction: Performance, mechanism insight and toxicity assessment

A novel double Z-type Cu-ZnO/BiOI/Bi2WO6 photocatalyst was synthesized using one-pot hydrothermal method. The effects of Bi2WO6 and Cu-ZnO contents, antibiotic concentration, catalyst dosage, solution pH value, coexisting ions, antibiotic types, mixed antibiotic types, water source and light source on the catalytic performance of the Cu-ZnO/BiOI/Bi2WO6 were investigated. Remarkably, under visible light irradiation, the removal rate of 20 mg/L norfloxacin reached 94.32 % within 120 min using the optimized Cu-ZnO/BiOI/Bi2WO6 photocatalyst, and its pseudo-first-order reaction rate constants were 5.63 and 1.80 times higher than those of BiOI and BiOI/Bi2WO6, respectively. The toxicity prediction and experimental findings indicated that the toxicity of the degraded norfloxacin (NOR) solution was notably diminished. The Cu-ZnO/BiOI/Bi2WO6 catalyst exhibited excellent salt tolerance, high reusability stability, universality and spectral response. Outstanding photocatalytic performance of Cu-ZnO/BiOI/Bi2WO6 photocatalyst is primarily due to the co-recombination of Cu-ZnO and Bi2WO6 on BiOI, which increases the surface area and active sites of the catalyst. More importantly, the double Z-type heterojunction, created through the intimate union of the semiconductor boundary within the composite catalyst, enhances the interface charge transport efficacy and the efficiency of separating photogenerated carriers. Finally, in conjunction with a diverse range of experimental methodologies, the degradation pathway of NOR through the Cu-ZnO/BiOI/Bi2WO6 composite catalyst and the electron transfer mechanism within the double Z-type heterojunction have been comprehensively elucidated. This study provides a pioneering reference for optimizing BiOI-based heterojunction catalysts and addressing antibiotic-contaminated wastewater treatment.

Novel biomass carbon dots/chitosan hydrogel-modified TiO2: An effective reduction of Cr(VI) in various wastewater under sunlight

Hexavalent chromium (Cr(VI)) poses a serious threat to the environment and human health owing to its inherent toxicity. Photocatalysis technology has garnered widespread attention owing to its efficiency and environmental friendliness. However, existing photocatalysts are constrained by light conditions, low reduction rates, and lack of studies in real wastewater. In this study, biomass carbon dots (P-CDs) were synthesized from peanut shell powder, then combined with chitosan (CS) and TiO2 to create a novel photocatalyst (9:1 1 % P-CDs/TiO2@CS). The photocatalyst exhibited a smaller band gap and a broader light absorption range than TiO2, while the porous structure of the hydrogel increased the contact area between P-CDs/TiO2@CS and Cr(VI), thereby enhancing its photocatalytic performance. Our study demonstrates that under simulated sunlight using a xenon lamp, 0.2 g of 9:1 1 % P-CDs/TiO2@CS reduced 50 mg/L Cr(VI) at a rate of 99.64 % in 30 min (pH 7). The photocatalyst also exhibited excellent reduction capabilities for Cr(VI) across a pH range (pH 2–9), at different concentrations (10, 20, 30, 40, 50, and 60 mg/L), and in various real wastewater samples (influent, effluent, and electroplating wastewater). After five cycles, the reduction rate was still maintained at 90.38 %. Experiments conducted under natural sunlight and ion interference further confirmed its outstanding photocatalytic performance and stability in real-world applications. Free radical trapping experiments indicated that electrons (e-) and holes (h+) were the primary active species. Additionally, antibacterial experiments showed that the reactive oxygen species generated by the photocatalyst under light irradiation effectively inhibited the proliferation ofEscherichia coli. Thus, P-CDs/TiO2@CS holds significant potential for practical application in environmental wastewater treatment.

Hydroxyl-enriched hydrous tin dioxide-coated BiVO4 with boosted photocatalytic H2O2 production

The rapid decomposition of H2O2 on the surface of inorganic photocatalyst (BiVO4) and insufficient proton supply from water leads to a low photosynthetic yield of H2O2. Herein, hydrous tin dioxide (HSnO) with massive hydroxyl groups was coated on the BiVO4 surface to greatly improve the photocatalytic H2O2 activity via simultaneous realization of providing sufficient protons and inhibiting H2O2 decomposition. After the coating of HSnO, Au nanoparticles as the O2-reduction active sites were selectively deposited on the (010) facet of BiVO4 to synthesize the Au/BiVO4@HSnO photocatalyst. The resulting Au/BiVO4@HSnO photocatalyst exhibits excellent H2O2-production performance, in which the photogenerated H2O2 concentration (210.7 ​μmol ​L−1) is about 4.8 times higher than that of the Au/BiVO4 after 2 ​h light irradiation in pure water. The outstanding photocatalytic performance can be attributed to simultaneous enhancement of H2O2 generation and the suppression of H2O2 decomposition by HSnO coating. Specifically, the HSnO coating with massive hydroxyl groups provides enough protons to promote the catalytic transformation of O2 into H2O2 on Au nanoparticles. More importantly, the HSnO coating not only allows water macular to effectively permeate onto BiVO4 surface for rapid oxidation reaction, but also greatly inhibits the reverse reaction of H2O2 decomposition via decreasing its affinity with BiVO4 surface. This research offers new insights for boosting photocatalytic H2O2 production through surface coating strategy.

Boosting charge separation and active sites exposure by hollow S-scheme MoSe2/Fe2O3 heterojunction for enhanced photocatalytic peroxymonosulfate activation towards ciprofloxacin removal

Regulating the properties of heterogeneous catalyst for efficient peroxymonosulfate (PMS) activation to pollutants degradation remains a challenge in photo-assisted Fenton-like reaction (PF) system. In this study, the novel S-scheme MoSe2/Fe2O3 (H-FMS) heterojunction with hollow nanostructure was successfully developed as visible-light-driven PMS activator for removal of ciprofloxacin (CIP). The prepared H-FMS catalyst in PMS/H-FMS/light system exhibits outstanding photocatalytic performance for CIP degradation, achieving 95.92 % removal of 5 mg/L CIP in 30 min with 0.5 mM PMS. The construction of S-scheme heterojunction provides photoinduced carriers with longer lifetime and higher redox abilities, thus sufficient photogenerated carriers are supplied to directly activate PMS. Simultaneously, the hollow nanostructure possessing multiple light reflection and scattering behaviors further facilitates the utilization of visible light. More importantly, high concentration of photoinduced electrons with high reduction ability in MoSe2 is conducive to continuous exposure of Mo4+ active sites for PMS activation through cycling between transition metal valence states. Overall, effectively separated electron-hole pairs and continuously exposed transition metal active sites both contribute to efficient activation of PMS as well as multi-path generation of ROS, leading to significant improvement in CIP degradation. The results of quenching experiment, electron spin resonance (ESR) technology, liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT) calculation confirm that both free radicals (SO4∙-, •OH and O2∙-) and non radicals (1O2 and h+) attack the active sites of CIP possessing high Fukui index, thus contributing to CIP degradation. This work would provide a novel insight for future development and application of photocatalytic PMS activation catalysts in water remediation.

Design of ternary GO@AgNPs@g-C3N4 membranes for efficient dye removals in integrated photocatalysis-filtration reactors

Photocatalytic composite membranes (PCMs), which integrate the high degradation efficiency of photocatalysts and the physical separation properties of membranes, have emerged as a promising technology for wastewater treatment. Herein, the ternary GO@AgNPs@g-C3N4 PCM was fabricated through a facile vacuum-filtration assembly of graphene oxide (GO), graphitic phase carbon nitride (g-C3N4), and silver nanoparticles (AgNPs) onto commercial mixed cellulose ester (MCE) substrates. The effects of g-C3N4 synthesized from different precursors and various metal nanoparticles on the performance of PCM were systematically investigated. Interestingly, results show the addition of AgNPs not only significantly improves the photocatalytic performance of PCMs but also enhances the mechanical adhesion between the active layer and the MCE substrate. The resultant PCMs exhibit outstanding photocatalytic performance, maintaining dye removal above 89% even after 25 consecutive cycles. Moreover, dye degradation pathways over the PCMs were investigated through free radical scavenging experiments and electron spin resonance characterizations. This simple assembly method results in a 3–12 times increase in flux compared to the layer-by-layer assembly method. Accordingly, our designed PCMs exhibit significant potential for wastewater treatment and water purification applications.

Construction of sulfur-chloride co-doped triazine/heptazine homojunction carbon nitride photocatalyst for simultaneous production of H2O2 and lignin C-C bond cleavage

Photocatalytic H2O2 production and cleavage of lignin C-C bonds is a typical strategy that follows sustainable development. Unfortunately, the photocatalytic efficiency of these two reactions still faces significant challenges. Herein, a carbon nitride photocatalyst (tri/hep-CN) with sulfur-chloride co-doped triazine and heptazine structures was synthesized. It was simultaneously used for photocatalytic H2O2 production and lignin C-C bond cleavage. In the air atmosphere, the yield of H2O2 reached 1171.9 μmol•g−1•h−1 after the addition of β-1 lignin model 1,2-diphenylethanol (Dpol) to the solvent. The yield of H2O2 increased by 20 times compared with no addition of Dpol. The lignin C-C bond in Dpol is also efficiently broken, producing benzaldehyde and benzyl alcohol. tri/hep-CN has excellent photogenerated carrier separation efficiency and positive valence potential, which improves the photocatalytic H2O2 production and lignin C-C bond cleavage performance. Notably, coupling photocatalytic H2O2 production with lignin C-C bond cleavage to fully use photogenerated electrons and holes is also very important to obtain outstanding photocatalytic performance. Mechanistic studies have shown that photocatalytic H2O2 production follows an indirect reaction mechanism. Meanwhile, the cleavage of lignin C-C bond follows the Cβ radical mechanism and the single electron transfer mechanism. This work is very instructive for simultaneous photocatalytic H2O2 production and lignin C-C bond cleavage studies.

The coexistence of highly dispersed Pt2+ and Pt0 co-catalysts on chemically oxidized g–C3N4 via metal-support interaction: The effect of reduction time on Pt species and hydrogen evolution of Pt/g-C3N4 photocatalysts

Platinum (Pt) cocatalyst greatly enhances the photoactivity of the graphitic carbon nitride (g-C3N4) photocatalyst for photocatalytic H2 evolution where the Pt properties are critical to determine the photocatalytic activity. In this study, highly dispersed Pt was successfully loaded onto chemically oxidized g–C3N4 (OCN) via a hydrogen reduction process over different reduction time. OCN photocatalysts containing highly dispersed Pt2+/Pt0 exhibited outstanding charge separation efficiency and photocatalytic performance. Symmetrical –CO groups on the OCN surface specifically interacted with atomic Pt2+, and the Pt2+ atoms were stably reduced to Pt0 atoms along with the generation of –OH groups over time. The coexistence of Pt0 and Pt2+ promoted superior photocatalytic performance because the photoinduced charge transfer was facilitated by the Pt0 atoms, which was evidenced by the DFT calculation and the EIS, PL, and photocurrent response results. Consequently, after the 24 h reduction, the highly stable and active Pt2+/Pt0 atoms were effectively distributed over OCN, resulting in the highest HER activity at 4091.3 µmol g−1 h−1.

Cd0.9Zn0.1S/NiB Schottky heterojunction for efficient photothermal-assisted photocatalytic hydrogen evolution

Within the theoretical framework of computational prediction, this study introduces a novel tetrapodal Cd0.9Zn0.1S/NiB (CZS/NiB) Schottky heterojunction material, which demonstrates exceptional photothermal effects and remarkable photocatalytic properties. Notably, under visible light irradiation for 3 h, the photocatalytic hydrogen evolution activity of CZS/NiB-3 % surpasses that of pure CZS by a factor of 10.52. This outstanding photocatalytic hydrogen production performance stems from the successful construction of the CZS/NiB-3 % Schottky heterojunction with promoted the separation and transfer of photogenerated charge carriers and excellent photothermal effect. Additionally, the synthesized CZS/NiB exhibits high photostability and cycling stability. The favorable photothermal effect of the synthesized photocatalyst was experimentally validated through infrared thermography technology. Through in-depth computational investigations using density functional theory, the pathways of charge transfer in the Schottky heterojunction are validated. This study provides a feasible strategy for research on photocatalytic water splitting for hydrogen evolution.

Boosting Photocatalytic CO2 Methanation through Interface Fusion over CdS Quantum Dot Aerogels.

In the field of photocatalytic CO2 reduction, quantum dot (QD) assemblies have emerged as promising candidate photocatalysts due to their superior light absorption and better substrate adsorption. However, the poor contacts within QD assemblies lead to low interfacial charge transfer efficiency, making QD assemblies suffer from unsatisfactory photocatalytic performance. Herein, a novel approach is presented involving the construction of strongly interfacial fused CdS QD assemblies (CdS QD gel) for CO2 reduction. The novel CdS QD gel demonstrates outstanding photocatalytic performance for CO2 methanation, achieving a CH4 generation rate of ≈296 µmol g-1 h-1, with a selectivity surpassing 76% and an apparent quantum yield (AQY) of 1.4%. Further investigations reveal that the robust interfacial fusion in these CdS QDs not only boosts their ability to absorb visible light but also significantly promotes charge separation. The present work paves the way for utilizing QD gel photocatalysts in realizing efficient CO2 reduction and highlights the critical role of interfacial engineering in photocatalysts.

Inhibition of the growth rate of ZnS anode crystal plane: boosting photocatalytic hydrogen production performance

The catalyst's particle size plays a crucial role in enhancing photocatalytic performance. However, it is still unclear to analyse the mechanism by which surfactants affect the particle size of photocatalysts from the perspective of crystal growth. Herein, ZnS nanomaterials with different particle sizes were synthesized using a simple solid-state chemical synthesis method, and the intrinsic influence mechanism between surfactant and catalyst particle size was analyzed from the perspective of crystal growth. It was discovered that the particle size of ZnS kept getting smaller due to changes in polyethylene glycol, cetyltrimethylammonium bromide, and sodium dodecyl sulfate. Analyzing the reasons revealed that the catalyst's particle size was related to the type of surfactant: anionic surfactants could reduce the catalyst size. Correspondingly, the catalyst with a smaller particle size has the optimal performance for photocatalytic hydrogen production. Photocatalysts Z-SDS exhibited outstanding photocatalytic performance, yielding 11.47 mmol/g of hydrogen after a five-hour illumination. Furthermore, the intrinsic influence mechanism between anionic and cationic surfactants, photocatalyst particle size, and catalytic performance was investigated. This investigation provides a new idea for synthesizing small-size and high-performance photocatalysts.

Facile synthesis of Fe/W co-doped MoO3 nanomaterial for proficient photocatalytic, enhanced sensing, superior luminescence and antioxidant activities

We report a new, easy and environment friendly defects engineered approach to develop defect-rich Fe/W co-doped MoO3 nanoparticles (Fe,W-MoO3 NPs) for a variety of applications. The solution combustion process entails using Millettia peguensis flowers extract as a unique fuel for the synthesis of Fe,W-MoO3 NPs. The synthesized NPs were characterized by various physical techniques. As prepared NPs were well examined for photocatalytic methylene blue (MB) dye degradation, electrocatalytic nitrite sensing, antioxidant and luminescence performances. Under visible light irradiation, Fe,W-MoO3 NPs exhibit outstanding photocatalytic performance towards MB dye degradation. Complete degradation of MB dye was demonstrated by the photocatalyst within a short span of 30 min. Cyclic voltammetry (CV) and linear sweep voltammetry studies were carried out to assess the electrocatalytic performance of as synthesized NPs. The Fe,W-MoO3 fabricated electrode manifested substantial nitrite sensing activity with LOD of 23.36 ± 1.17 µM. Fe,W-MoO3 nanoparticles demonstrated significant DPPH antiradical properties with IC50 of 394.33 ± 19.17 μg/mL. Also, as synthesized NPs exhibited significant luminescence activity portraying it as an efficient luminescent material. Thus, the current work manifests an inexpensive and sustainable green synthetic approach for large-scale synthesis of multifaceted Fe,W-MoO3 NPs.

Hierarchical heterojunction comprising of in-situ derived TiO2 and salicylaldimine-supported Co catalysts in metal-organic frameworks for enhancing photocatalytic hydrogen generation

We present the design of a novel functional metal-organic framework here, denoted as Co-sal–NH2–MOF@TiO2, featuring the comprise of controllably in-situ grown TiO2 sheets from NH2-MOF(Ti) and [Co] catalytic sites stabilized by salicylaldimine moiety via site isolation for visible-light-driven hydrogen evolution from water. The hierarchical organization of TiO2 and Co catalyst within NH2-MOF (Ti) leads to outstanding photocatalytic performance, as evidenced by a H2 yield of 15,584 μmolg−1h−1 and turnover numbers (TON) reaching 5844 over 24 h. This catalyst also signifies distinctly enhanced activities of approximately 105-fold, 354-fold, 15-fold, and 100-fold, compared to the pristine NH2-MOF(Ti), MOF-derived TiO2, NH2-MOF(Ti)@TiO2 and the combination of [Co catalyst + NH2-MOF(Ti) + TiO2], respectively. EXAFs and XPS etc. analyses revealed a stable coordination environment for salicylaldimine-supported Co(II) catalytic unit, which integrated with in-situ grown TiO2 sheets can not only guarantee catalyst stability, but also generate much more densely packed light-harvesting heterojunction units and thus promote separation and transfer of photogenerated carriers between TiO2 and Co catalyst in NH2-MOF(Ti) under light through optimized band gap structure. This work outlines the in-situ construction of organic and inorganic hybrid heterojunction for H2 production from water.

Designing Bi2O3-Sn3O4 Z-scheme heterojunction on TiO2 NTs for improving photocatalytic performance

The design of semiconductor heterostructures as the effective strategy are recognized to enhance the photocatalytic capacity of photocatalysts for the settlement of energy shortage and pollutant treatment. To efficiently utilize solar energy, the Bi2O3-Sn3O4 nanoparticles with the Z-scheme energy band structure were synthesized on TiO2 nanotube arrays (TiO2 NTs) by the solvothermal deposition method. The TiO2 NTs/Bi2O3-Sn3O4 exhibited the outstanding photocatalytic dye degradation and Cr(VI) removal, which was much higher than those of single Bi2O3 or Sn3O4 sensitized samples. The H2 evolution test indicated that the Bi2O3-Sn3O4 cosensitization dramatically enhanced the photocatalytic H2 generation ability of TiO2 NTs with the rate of 58.75 μmol·h−1·cm−2. The high photoelectric conversion was also confirmed, and the outstanding photocatalytic performance was further revealed by the contrast experiment. The plausible photocatalytic mechanism based on the ESR and capturing experiments indicated that the Z-scheme energy band structure induced the photoelectron separation and the generation of O2 and OH radicals, which was the decisive role for the improved photocatalytic performance.

Enhanced photoelectrochemical sensor for dopamine detection based on MOFs-derived ZnO and TpPa-1 heterostructure composite

This study used ZIF-8 metal–organic framework as a precursor to create a N-doped ZnO. Subsequently, covalent organic framework named TpPa-1 (Tp, 1,3,5-triformylphloroglucinol; Pa-1, p-phenylenediamine) with a ZnO heterostructure composite (ZnO/TpPa-1) was created through an in-situ synthesis approach. Due to its superior band structure and outstanding photocatalytic performance, the ZnO/TpPa-1 composite is a good candidate for the development of a new type of photoelectrochemical (PEC) sensor for the detection of dopamine (DA). According to experimental data, ZnO/TpPa-1/ITO had a photocurrent that was roughly 1.5 times higher than TpPa-1/ITO and 4.5 times higher than ZnO/ITO. The primary reason for this improvement was the synergistic effects brought about by effective light usage and charge transfer at the interface between the TpPa-1 π-conjugated backbone and ZnO porous structure. The determination ranges for DA demonstrated two linear ranges, 0.005–0.25 μmol/L and 0.25–1.00 μmol/L, and the detection limit was as low as 1.3 nmol/L. Moreover, the PEC sensor exhibited good stability, selectivity, repeatability, and suitability for real-world samples. This work provides important new understandings for covalent organic framework (COF)-based heterostructure design, which can be used to improve PEC sensor performance.

Efficient photocatalytic hydrogen evolution of Z-scheme BiVO4/ZnIn2S4 heterostructure driven by visible light

Solar hydrogen production photocatalysis technology faces a significant challenge in designing and synthesizing efficient photocatalysts to achieve rapid migration of photo-induced charge carriers. This study introduces a method for preparing a BiVO4/ZnIn2S4 (BZS) Z-scheme photocatalyst through cation-exchange and low-temperature water bath synthesis. This system accelerates the separation and migration of photo-induced charges to precisely adjust the redox centers at the BiVO4/ZnIn2S4 heterogeneous interface, enhancing the redox capabilities of both holes and electrons. Consequently, the BiVO4/ZnIn2S4 heterojunction demonstrates outstanding photocatalytic performance. It reveals that BZS-0.3 (with 0.3 mmol BiVO4) achieves a photocurrent density of 0.42 mA cm−2 at 1.70 V vs. NHE (8.4 times that of BiVO4) and exhibits superior hydrogen evolution performance under visible light, reaching 2243 mmol g-1h−1 (19 times that of BiVO4). Cyclability tests confirm the good stability of BZS-0.3, offering a promising photocatalyst for efficient hydrogen production and presenting a new strategy for developing exceptional photocatalytic materials.

Structural Distortion of g-C3N4 Induced by a Schiff Base Reaction for Efficient Photocatalytic H2 Evolution.

Photocatalytic H2 evolution by water splitting is a promising approach to address the challenges of environmental pollution and energy scarcity. Graphitic carbon nitride (g-C3N4) has emerged as a star photocatalyst because of its numerous advantages. To address the limitations of traditional g-C3N4, namely its inadequate visible light response and rapid recombination of photogenerated carriers, we employed a schiff base reaction to synthesize -C=N- doped g-C3N4. The introduction of -C=N- groups at the bridging nitrogen sites induced structural distortion in g-C3N4, facilitating n-π* electronic transitions from the lone pair electrons of nitrogen atom and extending light absorption up to 600 nm. Moreover, the presence of heterogeneous π-conjugated electron distribution effectively traps photogenerated electrons and enhances charge carrier separation. Benefiting from its expanded spectral response range, unique electronic properties, increased specific surface area, the doped g-C3N4 exhibited outstanding photocatalytic H2 evolution performance of 1050.13 μmol/g/h. The value was 5.9 times greater than the pristine g-C3N4.