UV Vis Light Irradiation Research Articles

Facile synthesis of CuOx-decorated TiO2 nanoparticles via oxygen-limited pyrolysis of Cu(II) complex for efficient photocatalytic hydrogen evolution

CuOx-decorated TiO2 (CuOx/TiO2) nanoparticles have been prepared by the pyrolysis of Cu(II) complex on TiO2 in an oxygen-limited atmosphere. A solution phase deposition method combined with freeze drying was employed for depositing the 2-methylimidazole-Cu(II) complex onto TiO2 nanoparticles. The effect of decoration of CuOx on TiO2 nanoparticles in terms of the crystal phase, morphology, chemical compositions, surface area, surface elemental states, optical absorption and emission properties, was investigated using a series of characterization tools. The oxygen-limited pyrolysis of 2-methylimidazole resulted in the reduction of partial Ti4+ and Cu2+ ions into Ti3+, Cu+ and Cu0 species, respectively. The surface decoration of CuOx was found to improve the separation and migration of photogenerated electron-hole pairs and increase the life time of excitons. Furthermore, the photocatalytic performance of CuOx/TiO2 nanoparticles was evaluated for hydrogen evolution in aqueous methanol solution under UV–visible light irradiation. The CuOx/TiO2 photocatalyst with the optimal cocatalyst loading achieved hydrogen evolution rate of 4.34 mmol h−1 g−1, with 71- and 5.5-fold enhancement in activity over neat TiO2 and CuOx/P25, respectively. It is expected that the combination of deposition and pyrolysis of 2-methylimidazole-Cu(II) complex could be an effective approach for the decoration of Cu and its oxides on other supports.

Cobalt Phosphide-Supported Single-Atom Pt Catalysts for Efficient and Stable Hydrogen Generation from Ammonia Borane Hydrolysis.

Ammonia borane (AB) has emerged as a promising chemical hydrogen storage material. The development of efficient, stable, and cost-effective catalysts for AB hydrolysis is the key to achieving hydrogen energy economy. Here, cobalt phosphide (CoP) is used to anchor single-atom Pt species, acting as robust catalysts for hydrogen generation from AB hydrolysis. Thanks to the high Pt utilization and the synergy between CoP and Pt species, the optimized Pt/CoP-100 catalyst exhibits an unprecedented hydrogen generation rate, giving a record turnover frequency (TOF) value of 39911 and turnover number of 2926829 at room temperature. These metrics surpass those of all existing state-of-the-art supported metal catalysts by an order of magnitude. Density functional theory calculations reveal that the integration of single-atom Pt onto the CoP substrate significantly enhances adsorption and dissociation processes for both water and AB molecules, thereby facilitating hydrogen production from AB hydrolysis. Interestingly, the TOF value is further elevated to 54878 under UV-vis light irradiation, which can be attributed to the efficient separation and mobility of photogenerated carriers at the Pt-CoP interface. The findings underscore the effectiveness of CoP as a support for single-atom metals in hydrogen production, offering insights for designing high-performance catalysts for chemical hydrogen storage.

Low-crystallinity porous Ni2P2O7 nanowires with excellent CO2 capture ability for highly-efficient CO2 reduction

In this study, we prepared the porous Ni2P2O7 nanowires with low-crystallinity (LC-NPO) and high-crystallinity Ni2P2O7 nanosheets (HC-NPO), and employed them for the first time as catalyst in the CO2 photoreduction reaction. The photocatalytic performance of them was tested under the UV–Vis light irradiation and compared with the TiO2 commercial powder (P25). The CO2 photoreduction experiments shown that the LC-NPO had the highest ability than the HCNPO and the P25. Specifically, with triethanolamine (TEOA) as the sacrificial agent, LC-NPO achieved CO and CH4 yields of approximately 56.06 and 12.13 μmol·g−1 after 4 h UV–Vis light irradiation, which were 4.67 and 5.00 times of P25, respectively. The experimental results, and Density Functional Theory calculations proved that the unique porous nanowire structure enables LC-NPO to have a larger specific surface area, higher quantity of oxygen defects, and superior CO2 capture ability compared to HC-NPO. These features maybe the primary reasons for the excellent CO2 photoreduction ability. Besides, the photo-electrochemical characterizations revealed that the LC-NPO had the much superior photoelectrochemical properties than the HC-NPO, which was another reason for enhanced photocatalytic ability. In-situ FTIR and 13C isotope labeling experiments were used to monitor the CO2 reduction process, and finally a potential enhanced mechanism had been discussed.

Synthesis, Structural Characterization, and Hirschfeld Surface Analysis of a New Cu(II) Complex and Its Role in Photocatalytic CO2 Reduction.

A new Cu(II) complex, [CuL1L2(CH3COO)2(H2O)]·H2O, was synthesized by the reaction of Cu(CH3COO)2·H2O, 6-phenylpyridine-2-carboxylic acid (HL1), and 4-[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]pyridine (L2) in ethanol-water (v:v = 1:1) solution. The Cu(II) complex was characterized using elemental analysis, IR, UV-vis, TG-DTA, and single-crystal X-ray analysis. The fluorescence properties of the copper complex were also evaluated. The structural analysis results show that the Cu(II) complex crystallizes in the triclinic system with space group P-1. The Cu(II) ion in the complex is five-coordinated with one O atom (O2) and one N atom (N1) from one 6-phenylpyridine-2-carboxylate ligand (L1), one N atom (N2) from 4-[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]pyridine ligand (L2), one O atom (O4) from acetate, and one O atom (O5) from a coordinated water molecule, and it adopts a distorted trigonal bipyramidal geometry. Cu(II) complex molecules form a two-dimensional layer structure through intramolecular and intermolecular O-H…O hydrogen bonding. The two-dimensional layer structures further form a three-dimensional network structure by π-π stacking interactions of aromatic rings. The analysis of the Hirschfeld surface of the Cu(II) complex shows that the H…H contacts made the most significant contribution (46.6%) to the Hirschfeld surface, followed by O…H/H…O, N…H/H…N and C…H/H…C contacts with contributions of 14.2%, 13.8%, and 10.2%, respectively. In addition, the photocatalytic CO2 reduction using Cu(II) complex as a catalyst is investigated under UV-vis light irradiation. The findings reveal that the main product is CO, with a yield of 10.34 μmol/g and a selectivity of 89.4% after three hours.

Enhanced Photocatalytic Activity of Surface‐Modified TiO2 with Bimetallic AuPd Nanoalloys for Hydrogen Generation

Herein, commercial titania (TiO2‐P25) is modified with mono‐ and bi‐metallic (Au, Pd, and AuPd) nanoparticles synthesized by chemical reduction method using NaBH4 as a strong reducing agent at room temperature. Bimetallic AuPd nanoalloys homogeneous in size and well dispersed on the TiO2 surface are obtained. The charge‐carrier dynamics, which is a key factor in photocatalysis, is studied by time‐resolved microwave conductivity. The results reveal that surface modification plays a crucial role in charge‐carrier separation, increasing the activity under UV–vis light irradiation. The bimetallic AuPd nanoalloys formation is confirmed by high‐angle annular dark field scanning transmission electron microscopy and corroborated by semiempirical molecular dynamics simulations (Gupta‐LAMMPS). The surface‐modified TiO2 with bimetallic AuPd nanoalloys exhibits higher photocatalytic activity compared to TiO2 modified with their monometallic counterparts. The experimental results are also supported by density functional theory and density functional tight binding calculations, which show that alloying AuPd with low Pd content presents significant synergetic effects for hydrogen generation under UV–vis light from aqueous triethanolamine solutions. Additionally, the AuPd/TiO2 photocatalysts are stable with cycling.

TiO2 nanorod decorated with MoS2 nanospheres: An efficient dual-functional photocatalyst for antibiotic degradation and hydrogen production

The design and preparation of dual-functional photocatalysts for simultaneously realizing photocatalytic wastewater purification and hydrogen energy generation pose significant challenges. This article presents the engineering of a binary heterostructured photocatalyst by combining TiO2 (nanorods) and MoS2 nanosphere using a straightforward solvothermal method and the assessment of the phase structures, morphologies, and optical properties of the resulting nanocomposites using diverse analytical techniques. The TiO2(Rod)/MoS2 composite exhibits remarkable efficacy in degrading ciprofloxacin, achieving 93% removal rate within 1 h, which is four times higher than that of bare TiO2. Moreover, the optimized TiO2(Rod)/MoS2 presents an outstanding hydrogen production rate of 7415 μmol g−1, which is ∼24 times higher than that of pristine TiO2. Under UV–visible light irradiation, the TiO2(Rod)/MoS2 heterojunction displays an exceptional photocatalytic performance in terms of both photodegradation and hydrogen production, surpassing the performance of TiO2 particle/MoS2. The study findings demonstrate that TiO2(Rod)/MoS2 nanocomposites exhibit considerably improved photocatalytic degradation and hydrogen generation activities. Based on the experimental results, a possible mechanism is proposed for the transfer and separation of charge carriers in Z-scheme heterojunctions.

Boosting Hydrogen Production through Water Splitting: N, Ni, and N-Ni Doped ZnO Photocatalysts

This work investigates the potential of N, Ni, and N-Ni-doped ZnO as photocatalysts for hydrogen production through water splitting. Sonochemical techniques were used to synthesize these materials. In contrast to undoped or singly-doped ZnO, N-Ni-double-doped ZnO demonstrated a significantly narrower band gap (2.89 eV) and smaller crystallites (21.60 nm). This led to a remarkable doubling in the hydrogen production rate under UV-visible light irradiation. The combined effect of N and Ni doping effectively promotes efficient charge separation and enhanced light absorption, resulting in significantly increased photocatalytic activity. Furthermore, N-Ni-ZnO demonstrates exceptional stability, retaining over 95% of its initial activity after five cycles. This work paves the way for the development of cost-effective and scalable photocatalysts for sustainable solar hydrogen production.

Integrated 2D Bi2O3/boron carbon nitride for improved photocatalytic water depollution

This study delves into the untapped potential of BCN (boron carbon nitride) as a photocatalyst, highlighting its remarkable porosity and bandgap adjustability. In pursuit of enhancing BCN's photocatalytic capabilities, we introduce an innovative approach to incorporate Bi2O3 nanoparticles onto BCN's surface through a thermal condensation process. The assessment of photocatalytic activity involved the degradation of both non-dye and dye compounds (acetaminophen, malachite green, and reactive blue) under UV–visible light irradiation. Our findings reveal that the Bi2O3/BCN (BiBCN) composites exhibit significantly improved photocatalytic activity compared to individual BCN or Bi2O3. Notably, the 5%BiBCN photocatalyst excels, achieving removal rates of 80.88 % for ACE, 98.6 % for MG, and 97.7 % for RB within 120 min under UV–Vis light exposure. Characterization unveils that the composite photocatalysts enhance the separation of photogenerated carriers, primarily attributed to the formation of heterojunctions. Our proposed mechanism underscores the synergy of increased specific surface area and the heterojunction formed by the interaction between Bi2O3 and TCN in enhancing photocatalytic performance. Altogether, this study sheds light on the promising potential of BCN-based heterojunction photocatalysts for efficient water depollution.

Boosting the piezo-photocatalytic performance of Na0.5Bi0.5TiO3 by modulating the oxygen vacancy concentration

The emergence of piezo-photocatalysis inaugurates a nascent approach aimed at mitigating the rapid recombination of electrons and holes, thus augmenting catalytic efficacy. This work endeavors to fabricate Na0.5Bi0.5TiO3 (BNT) nanosphere powders through a simplified hydrothermal method, whereby precise control over the quantity of tetrabutyl titanate, a titanium source, is employed. The piezo-photocatalytic performance of BNT nanospheres is meticulously scrutinized through the degradation of Rhodamine B (RhB) at a concentration of 5 mg/L, utilizing ultrasonic vibration and UV–visible light irradiation. Remarkably, the appropriate oxygen vacancies exerts a profound impact on the efficiency of piezoelectric photocatalytic degradation. Among the investigated catalysts, The material with the best performance exhibits the highest rate of piezo-photocatalytic degradation, boasting a rate constant (k value) of 0.052 min−1. Furthermore, the BNT nanospheres exhibit commendable stability and reusability in the context of piezo-photocatalytic degradation. Elucidation of the piezo-photocatalytic mechanism of BNT nanospheres is attained through the identification of radicals and intermediates present in the degradation process. This research imparts invaluable guidance for the design and development of state-of-the-art and high-performance piezo-photocatalytic catalysts.

Synthesis, Spectroscopy, X-ray Structures, DNA Binding and Photocatalytic Properties of Two Ni(II) and Co(II) Complexes of a Pyrazolyl Schiff-base Ligand

Two new nickel(II) and cobalt(II) complexes, [Ni(MPAFA)3](BF4)2 (I) and [Co(MPAFA)3](BF4)2 (II) were synthesized from a pyrazole containing ‘NN’ bidentate Schiff-base ligand, N-(furan-2-ylmethyl)-1-(5-methyl-1H-pyrazol-3-yl)methanimine, (MPAFA) (L). The complexes I and II were characterized by various physico-chemical and spectral parameters. Both I and II were 1:3 (M:L) coordination complexes and behaving as 1:2 electrolytes. Single crystal X-ray diffraction studies revealed that both of them were distorted octahedral in nature with a N6 donor set. The binding interactions of the complexes with CT-DNA were studied by UV-Vis and fluorescence spectroscopic methods. I was found to bind with CT-DNA in a partial intercalative mode, whereas II bound via the groove-like manner in solutions. The ligand and the complexes were shown to have potential photocatalytic activity in degrading methylene-blue (MB) under UV-Vis light irradiation.

Cobalt/Nitrogen-Doped carbon hollow spheres for highly efficient degradation of tinidazole with peroxymonosulfate

This study aimed to put forward a strategy to synthesize cobalt/N-Doped carbon hollow spheres (Co/NCHPs) with ample reactive sites. The zeolitic imidazolate framework-67 was loaded on the polystyrene nanosphere (PS@ZIF-67) as precursors, followed by a controlled pyrolysis to obtain Co/NCHPs with a large single hole on each sphere. The 1O2, SO4•−, O2•−, and •OH were identified as the main reactive oxygen species (ROSs) by electron paramagnetic resonance (EPR) experiments. It is also worth noting that electron transfer was also the main non-radical pathway for tinidazole (TNZ) degradation in Co/NCHPs/PMS systems. The effects of reaction conditions on TNZ degradation were investigated. 20 mg/L of TNZ was degraded within 6 min under UV–visible light irradiation. Besides, the degradation efficiency of four organic pollutants was higher than 95 % in different water matrices. Moreover, Co/NCHPs exhibited an exceptional photocatalytic performance for several antibiotics and organic dyes mixed solution in natural water. Furthermore, the recycling test of Co/NCHPs indicated that catalysts can be reused five times without obvious activity loss. This work provided a facile and large-scale preparation method to obtain Co/NCHPs.

Tea saponin-derived porous carbon bearing rich oxygen-containing groups towards high efficient CO2 fixation

The effective utilization of biomass resources can bring significantly environmental and economic benefits. In this context, tea saponin, which can be easily and extensively extracted from the oil cake as the biomass waste during the seed oil production from camellia seeds, is explored as the precursor to synthesize porous carbon bearing abundant –OH and –COOH groups via a simple carbonization process. Owing to the obtained porous structure and existence of rich oxygen-containing groups serving as Lewis acidic sites, the carbonized tea saponin (CTS) can display impressive catalytic activities for CO2 cycloaddition reaction with both high selectivity (> 99%) and high yield of target cyclic carbonate under either thermally driven (80 °C and 0.1 MPa CO2) or photo-thermally driven (UV-Vis light irradiation with the light intensity of 350 mW/cm2) conditions. In addition, benefiting from the good chemical stability, CTS can be reused for many cycles with almost no catalytic activity loss, making CTS a promising biomass-based catalyst for CO2 fixation under mild conditions.

Photoinduced Dual C-F Bond Activation of Hexafluorobenzene Mediated by Boron Atom.

The reaction of laser-ablated boron atoms with hexafluorobenzene (C6 F6 ) was investigated in neon and argon matrices, and the products are identified by matrix isolation infrared spectroscopy and quantum-chemical calculations. The reaction is triggered by a boron atom insertion into one C-F bond of hexafluorobenzene on annealing, forming a fluoropentafluorophenyl boryl radical (A). UV-Vis light irradiation of fluoropentafluorophenyl boryl radical causes generation of a 2-difluoroboryl-tetrafluorophenyl radical (B) via a second C-F bond activation. A perfluoroborepinyl radical (C) is also observed upon deposition and under UV-Vis light irradiation. This finding reveals the new example of a dual C-F bond activation of hexafluorobenzene mediated by a nonmetal and provides a possible route for synthesis of new perfluorinated organo-boron compounds.

Synthesis, properties and applications of sulfur doped (CdO)1-x(Mn3O4)x (x = 0.0/0.25/0.50/0.75/1.0) nanocrystals

Studies have been made to understand the effect of anionic doping (with 2.5 wt% sulfur) on the physicochemical properties and photocatalytic, and antimicrobial activity applications of the interesting and useful (CdO)1-x(Mn3O4)x (x = 0.0/0.25/0.50/0.75/1.0) nanocrystals (synthesized by a microwave-assisted solvothermal method, and annealed at 650 °C). X-ray diffraction, electron microscopic (SEM/TEM) and EDX spectral analyses have shown that the synthesized samples are of high phase purity having spherical shaped morphology with crystallite sizes in the range of 11–22 nm. UV–visible spectral (in the wavelength range 200–800 nm) and AC electrical measurements (in the temperature range 40–160 °C and with frequency range 100 Hz–1 MHz) have indicated tuning of optical and electrical properties on doping. Capability in photocatalytic degradation (with Methylene Blue dye under UV–visible light irradiation) and antimicrobial activity (against gram positive Bacillus Subtiles, gram negative Escherichia Coli and fungus Candida Albicans) have also been studied for the 10 samples (including the 5 un-annealed samples) considered.

Synthesis and characterization of azaborepin radicals in solid neon through boron-mediated C-N bond cleavage of pyridine.

The reactivity of pyridine is a complex topic due to its unique electronic structure. The reactions of atomic boron with pyridine molecules in solid neon have been investigated using matrix isolation infrared absorption spectroscopy. Three products (marked as A, B, and C) were observed and characterized through 10B, D and 15N isotopic substitution pyridine regents as well as quantum chemical calculations. In the reaction, the ground-state boron atom can attack the lone pair electrons of the nitrogen atom in the pyridine molecule, resulting in the formation of a 1-boropyridinyl radical (A). Alternatively, addition to the aromatic π-system of pyridine can occur in a [1,4] type, leading to the formation of a B[η2(1,4)-C5H5N] complex (B). Under UV-visible light (280 < λ < 580 nm) irradiation, these two compounds can further undergo photo-isomerization to form BN-embedded seven-membered azaborepin compounds (C). The observation of species A, B, and the subsequent photo-isomerization to species C is consistent with theoretical predictions, indicating that these reactions are kinetically favorable. This research provides valuable insights into the future design and synthesis of corresponding BN heterocyclic derivatives.

Dual role of silk fabric functionalized with polymer/GO-tungsten oxide nanocomposites as superwettable membranes and photocatalysts for removing dye contaminants and emulsion separation

BackgroundWastewater containing hazardous dye contaminants has aroused significant concern and poses a great challenge to membrane technology. Herein, a novel bio-inspired silk fabric membrane modified with L-histidine functionalized polyglycidyl methacrylate composited with graphene oxide and tungsten oxide (amino-PGMA/GO-WO2.72) was successfully produced to treat wastewater contaminants. MethodsAn urchin-like WO2.72 nanoparticle is synthesized using the hydrothermal method. The synthesized WO2.72 nanoparticles are composited with an amino-functionalized PGMA/GO via dispersion polymerization techniques. Finally, a flexible membrane is created by dip-coating silk fabric in the amino-PGMA/GO-WO2.72 nanocomposite solution. Significant findingsThe fabricated membrane showed excellent superhydrophilicity, underwater superoleophobicity, and outstanding performance in separating methylene blue (MB) dye-mixed emulsions under gravity with a high permeation flux of about 1690 ± 40 L m−2 h−1. The amino-PGMA/GO-WO2.72 modified silk fabric membrane showed remarkable stability, allowing the membrane to withstand a high separation efficiency of 99 %. Furthermore, the photo-responsive ability of the heterojunction GO-WO2.72 catalyst materials present in the modified membrane can lead to the reduction of toxic nitro phenols, degradation of various dyes and textile effluents wastewater with high photodegradation efficiency under UV–-visible and solar light irradiation.

Improved photocatalytic activity of graphene oxide modified Ag-TiO2 for degradation of piroxicam-20 and dehydrogenation of methanol under light irradiation

BackgroundGraphene oxide (GO), an atomic sheet structure made of sp2-bonded carbon atoms with superior optoelectronic, and catalytic properties, has attracted much interest. Incorporating a carbon-rich material, onto metal-loaded TiO2 is reported to increase the photocatalytic properties of resultant composites. MethodsThis research aimed at the deposition of different amounts (1–5 wt.%) of GO using the ultrasonication method on bare TiO2 and Ag (3 wt.%)-TiO2 (AT3) and studied their influence on piroxicam-20 degradation under visible light and methanol dehydrogenation under UV light. The prepared composites' structural, optical, and morphological properties were characterized using XRD, DRS, HR-TEM, FE-SEM, and XPS. Significant findingsHRTEM analysis confirmed the existence of GO layers and spherical-shaped Ag nanoparticles deposited over the TiO2 surface. GO(5 wt.%)@Ag(3 wt.%)-TiO2 (G5@AT3) displayed better photodegradation efficiency (78 %) (k = 0.0082 min−1) under 120 min, and GO(1 wt.%)@Ag(3 wt.%)-TiO2 (G1@AT3) composite produced higher amount (427 mmol) of H2 from photocatalytic dehydrogenation of CH3OH under 5 h relative to TiO2 (2 mmol), AT3 (166 mmol) and GO(5 wt.%)@TiO2 composite (GT5) (11 mmol). HRMS analysis was performed to identify the piroxicam-20 degradation intermediates. Thus, this research provides a proactive strategy highlighting the cooperative effect of Ag and GO loading to improve the photocatalytic efficiency of TiO2 photocatalyst using both UV–visible light irradiation.

Enhanced photocatalytic degradation, antimicrobial and anticancer efficiency of mycosynthesized TiO2 nanoparticles using Pleurotus ostreatus mushroom extract: An eco-friendly approach

This study is one such study where an eco-friendly approach has been followed in biosynthesizing TiO2NPs from Pleurotus ostreatus mushroom extract. Therefore, we object to biosynthesizing TiO2NPs and characterize them morphologically using UV, XRD, FTIR, FESEM, EDX, HR-TEM, AFM, and GCMS. The UV–visible spectroscopy absorption of synthesized TiO2NPs has peaked at 335 nm. The antibacterial activity was investigated by both isolated bacteria pathogens (gram-positive and gram-negative). The maximum growth inhibition zone was noted in S. mutans (14.3 ± 0.4), E. coli (14.1 ± 0.3), and S. epidermidis (13.3 ± 0.2). The in vitro cytotoxicity assay of TiO2NPs showed an IC50 value of 47.42 µg/mL against MG-63 cancer cells. The photocatalytic degradation of methylene blue by TiO2NPs was investigated under UV–visible light irradiation. Due to the NPs tiny size and high dispersion, a rapid degradation (between 30 and 180 min) of almost 84.24% was accomplished. Even after the photocatalyst was used three times, there was no discernible difference in the TiO2NPs photocatalytic activity. The synthesized TiO2NPs successfully destroyed the Methylene Blue (MB) dye in an aqueous solution, promising wastewater dye remediation. Therefore, our research shows for the first time that biosynthesis of TiO2NPs using P. ostreatus extract can be an excellent outcome for emerging multipurpose and organic products.

Photocatalytic degradation of pollutants by PbBiO2Cl/TiO2/CS membrane with UV–Vis light irradiation

The PbBiO2Cl/TiO2/CS composite membrane material was prepared by solvent thermal method and casting. The structure, morphology and optical properties of the PbBiO2Cl/TiO2/CS membranes were characterized by FTIR, XRD, XPS, SEM and DRS. It was shown that the PbBiO2Cl/TiO2/CS-2(PTC-2) exhibited excellent photodegradation with 97.4 % of tetracycline (TC) and 96.3 % of methyl orange (MO) in 120 min. The main reason for the favourable performance was the formation of composite membranes of PbBiO2Cl/TiO2/CS, which reduced electron-hole recombination and improved the improved light absorption properties. Meanwhile, it was found that light-generated free radicals (⋅O2–, ⋅OH and h+) play a key crucial role during photocatalysis. This study presents a simple strategy to construct photocatalyst membranes to activity enhancement for organic pollutants.

3D/2D photocatalyst fabricated from Pt loading TiO2 nanoparticles and converter slag-derived Fe-doped hydroxyapatite for efficient H2 evolution

H2 generation for partially substituting coke by the photocatalysts fabricated from steel slag presents a desirable approach to on-site carbon footprint reduction in the iron and steel-making industry, both environmentally and economically. However, achieving high photocatalytic H2 production activity is primarily limited by the scarcity of active sites due to a small specific surface area, inefficient charge transfer, and partly restricted by slow kinetics of the H2 generation reaction. In this study, 1 wt% Pt clusters are photo-reduced onto sub-15 nm TiO2 nanoparticles (TiO2-Pt) in 20 vol% methanol. Subsequently, the electrostatic assembling method has been employed to combine steel-making converter slag-derived Fe-doped hydroxyapatite (FeHAp) with TiO2-Pt, forming a type II 3D/2D TiO2-Pt/FeHAp heterojunction. Excellent connectivity between these two phases contributes to efficient charge separation, forming a built-in electric field that drives the photo-generated electrons to flow from FeHAp to the Pt cocatalyst on TiO2 nanoparticles through the type-II path. By the synergistic effects, including the large specific surface of sub-15 nm TiO2, Pt cocatalyst-offered rapid H2 generation kinetics,. and the heterostructure-provided enhancement of interfacial charge migration and separation, 60 mg TiO2-Pt/5FeHAp presents an enhanced H2 production activity in 120 mL of 10 vol% triethanolamine (TEOA), enabling the H2 generation rate (3026 μmol·g−1·h−1) to reach 1.85 and 75.78 times greater than that of pristine TiO2-Pt (1638 μmol·g−1·h−1) and FeHAp-Pt (40 μmol·g−1·h−1), respectively, under UV–visible light irradiation for 3 h at 8 °C and obtaining an apparent quantum yield of 4.72 % at 370 nm. This study provides a promising strategy for green hydrogen-based steel-making in the sustainable development of the steel industry.