High Hydrogen Production Activity Research Articles

Novel organic dibranched photosensitizers featuring spiro-fluorene for efficient hydrogen generation from water

Four new metal-free organic photosensitizers featuring either a mono-anchoring donor–π–acceptor (D–π–A) or di-anchoring donor–(π–acceptor)2 (D(–π–A)2) architecture containing a spirobifluorene or spiro[fluorene-9,9′-xanthene] central donor core was prepared. These photosensitizers were subsequently tested for their efficiency in the photocatalytic production of H2, in combination with a Pt/TiO2 catalyst. Additionally, electrochemical, photophysical, and computational studies were conducted. The computational studies were specifically carried out to ascertain the electronic distribution within the photosensitizers. The influence of the molecular design on the efficiency of H2 production was examined. The di-anchoring photosensitizers notably amplified the spectral response in the visible light region, reduce aggregation on TiO2 and enhanced charge transfer. Among the fabricated photocatalytic systems, the di-anchoring photosensitizers exhibited superior photocatalytic efficiency compared to their mono-anchoring counterparts. Among all the photosensitizers, the spiro[fluorene-9,9′-xanthene]-based di-anchoring photosensitizer X2 possessing photocatalytic system demonstrated remarkable performance, producing 406.3 μmol (10.07 mL) of hydrogen over a period of 47 h under blue light irradiation. This performance corresponds to a turnover number (TON) of 6674, a turnover frequency (TOFi) of 445 h−1, an initial hydrogen production activity (activityi) of 278140 and an apparent quantum yield (AQYi%) of 4.762. The bulky spiro[fluorene-9,9′-xanthene] component endowed the photosensitizers with photostability, as confirmed by their high hydrogen production efficiency over 152 h of extended irradiation, yielding 12.69 mL of hydrogen. This study revealed, for the first time, that the bulky spiro-fluorene structure contributes positive synergistic effects to hydrogen production. It demonstrates that dibranched photosensitizers containing spiro-fluorene are promising candidates for achieving high and stable hydrogen production activity.

Synthesis and Photoreforming Reaction of CdS Prepared from MOF Precursor

AbstractThe photoreforming reaction, which can produce hydrogen simultaneously with the decomposition of organic waste, is a promising method for resolving longstanding global issues such as the depletion of energy resources and climate change. However, ZnS photocatalysts, one of the most optimal catalysts for such reactions, has an inadequate visible‐light response; thus, the extensibility of the reaction is limited. In this study, CdS photocatalysts are prepared from metal–organic framework (MOF) precursors, that is, Cd‐MOFs. The prepared CdS exhibits high hydrogen production activity in the photoreforming of lignocellulosic biomass under quasi‐sunlight conditions. This activity is approximately 13.4 times that of the CdS prepared via the conventional hydrothermal method. Further, CdS can utilize light energy in the visible region of sunlight, providing a high quantum yield and demonstrating the potential for the extensibility of the reaction. The results of this study will facilitate the fabrication of novel materials for sustainable and efficient hydrogen production.

Constructing an Open-Structured J-Type ZnIn2S4/In(OH)3 Heterojunction for Photocatalytical Hydrogen Generation.

Constructing heterojunctions to separate photogenerated carriers is an effective strategy for improving the efficiency of photocatalytic reactions. A J-type heterojunction is a recently reported efficient anisotropic heterojunction. Herein, taking anisotropic ZnIn2S4 (ZIS) nanosheets as an example of a type-II heterojunction, we report for the first time the concept of open and closed structures (O and C structure) of J-type heterojunctions. A simple ammonia-post-treatment method was employed to prepare the O- and C-structured J-type ZnIn2S4/In(OH)3 (ZIS/IOH) heterojunctions. The O-structured J-type ZIS/IOH (OJ-ZIS/IOH) heterojunction exhibits a high hydrogen production activity, reaching 400 μmol·h-1, 2.67 times higher than that of pristine ZIS. However, the activity of the C-structured heterojunction (CJ-ZIS/IOH) is close to that of pristine ZIS. The findings emphasize the importance of the cooperation of photogenerated carrier separation and transport in J-type heterojunctions, providing insights into developing efficient heterojunction photocatalysts.

A simple sol–gel method for the synthesis of Pt co-catalyzed spinel-type CuFe2O4 for hydrogen production; the role of crystallinity and band gap energy

In this investigation, spinel-type copper ferrites (CuFe2O4) at different calcination temperatures (600–900 °C) were produced using a facile citric acid-assisted sol–gel method. The crystal structure, morphology, optical, and electrical properties of the as synthesized photocatalysts were comprehensively characterized. XRD and UV–vis diffuse reflectance spectra (UV–vis (DRS)) showed that the phase structure and the band gap energy of the copper ferrite are strongly correlated to the applied calcination temperature. TEM results investigated that the copper ferrites calcined at higher temperatures presented large particle sizes and crystallized very well. In addition, the photocatalytic activity was tested for hydrogen production in the presence of methanol, with and without Pt nanoparticles as a cocatalyst. The results indicated that the CuFe2O4 annealed at 900 °C (CuF-900) has higher hydrogen production activity than photocatalysts calcined at lower temperatures in the presence and absence of Pt, which is mainly assigned to the higher crystallinity, and narrower bandgap energy. Moreover, this study explained in more detail the role of Pt nanoparticles in enhancing the photocatalytic activity of CuF-900. This work introduces a new direction of thinking for the tetragonal phase structure as an efficient photocatalyst for hydrogen production.

Enhanced photocatalytic hydrogen production from Co-MOF/CN by nitrogen and sulfur co-doped coal-based carbon quantum dots

A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots (NSCQDs) nanoparticles on the surface of sheet cobalt-based metal-organic framework (Co-MOF) and graphitic carbon nitride (g-C3N4, CN). The structure and properties of the obtained catalysts were systematically analyzed. NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region. The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254 μmol/(g·h) at pH = 9. At the same time, NSCQDs synergy Co-MOF/CN composites have good stability. After four cycles of hydrogen production, the performance remains relatively stable. The transient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts. The semiconductor type (n-type semiconductor) of the single-phase catalyst was determined by the Mott–Schottky test, and the band structure was analyzed. The conductive and valence bands of CN are −0.99 and 1.72 eV, respectively, and the conduction and valence bands of Co-MOF are −1.85 and 1.33 eV, respectively. The mechanism of the photocatalytic reaction can be inferred, that is, Z-type heterojunction is formed between CN and Co-MOF, and NSCQDs was used as cocatalyst.

Constructing fast charge separation of ZnIn2S4 @CuCo2S4 p-n heterojunction for efficient photocatalytic hydrogen energy recovery from quinolone antibiotic wastewater

Dual-functional catalysts can realize effective photocatalysis for synergistic water remediation and H2 production by coupling reduction and oxidation reaction in one water-pollutant system. In this work, a novel ZnIn2S4 @CuCo2S4 nanoflower-like p-n heterojunction catalyst was successfully synthesized by a simple method and used for hydrogen generation from quinolone antibiotic wastewater. ZnIn2S4 @CuCo2S4 exhibited high hydrogen production activity of 0.36 mmol·g−1·h−1 in ofloxacin (OFL) solution. Simultaneously, the OFL removal efficiency and mineralization rate were up to 89.4 % and 92.24 %, respectively. The interface charge transfer mechanism was thoroughly investigated through systematic characterizations and DFT calculations. The results show that CuCo2S4 addition significantly improved the separation and transfer rate of photoinduced carriers. Additionally, the possible degradation pathways of OFL were analyzed using LC-MS. This study provides a new approach for simultaneous energy conversion and environmental pollution treatment, offering a new pathway for achieving sustainable energy development through the management of antibiotic wastewater.

Self-optimized H-adsorption affinity of CuRu alloy cocatalysts towards efficient photocatalytic H2 evolution

In addition to the electron transfer, the appropriate H-adsorption affinity of active centers on the metal cocatalyst surface is quite important for high hydrogen-production activity of cocatalyst-modified photocatalysts. The typical Cu and Ru metal cocatalysts clearly exhibit a weak Cu–H bond and a strong Ru–H bond, respectively, resulting in limited activity for photocatalytic H2 evolution. In this work, an ingenious strategy of self-optimized H-adsorption affinity in CuRu alloy cocatalyst is developed to simultaneously reinforce the Cu–H bond and weaken the Ru–H bond by the intrinsic electron transfer from Cu to Ru atom. The CuRu alloy nanoparticles (2–3 nm) were deposited on the TiO2 surface to prepare CuRu/TiO2 through a one-step photoreduction method. Photocatalytic tests exhibited that the highest H2-production rate of CuRu/TiO2 photocatalyst reached up to 5.316 mmol h–1 g–1, which was 24.80, 1.86, and 2.60 times higher than that of the TiO2, Cu/TiO2, and Ru/TiO2, respectively. Based on the characterization results and theoretical calculations, the CuRu alloy cocatalyst exhibits excellent self-optimized H-adsorption affinity via the spontaneous electron transfer from Cu to Ru atom, which can greatly accelerate the photocatalytic H2-production rate of TiO2. This work provides a feasible idea for the self-optimized H-adsorption affinity of metal active sites in the photocatalytic H2-generation field.

An Integrated Plasma-Photocatalytic System for Upcycling of Polyolefin Plastics.

Nondegradable polyolefin plastics, which account for >60 % of total plastic waste, trigger severe global concerns and thus demand effective management technologies. However, owing to the chemical inertness of non-polar C-C backbones in the polyolefin structure, efficient upcycling of polyolefin plastics under ambient conditions remains a great challenge. This study introduces an integrated plasma-photocatalytic technology, coupling plasma treatment with solar-driven reforming under mild conditions, for the efficient upcycling of polyolefin plastics into value-added hydrogen and gaseous fuels. The first plasma step grafts oxygenated groups, such as -OH, O-C=O, and C=O, onto the polyolefin chains, which leads to the formation of a polar and hydrophilic polymer that facilitates the subsequent reforming in the photocatalytic step. Therefore, high hydrogen production activity with a benchmark efficiency of >100 μmol g-1 h-1 was achieved. Moreover, the integrated process also demonstrates high versatility in upcycling different polyolefin plastics including polyethylene, polypropylene and polyvinyl chloride. The findings provide a new avenue for plastic upcycling in an efficient and sustainable way.

Interfacial Interaction of Monolayer Black Phosphorus/g‐C3N4 Van Der Waals Heterojunction for Efficient Photocatalytic Hydrogen Evolution

The 2D/2D van der Waals heterojunctions have promising photocatalytic applications. However, their interfacial interaction and photocatalytic mechanism are still unclear. Herein, monolayer black phosphorus (BP)/graphitic carbon nitride (GCN) heterojunction photocatalytic hydrogen evolution is systematically investigated using the density‐functional theory method. It is indicated in the results that BP/GCN heterojunction structure distortion and interface interaction change its electronic structure and photocatalytic performance. The hydrogen‐adsorption free energy of BP/GCN heterojunction is −0.28 eV, indicating that the BP/GCN heterojunction has a high catalytic activity for hydrogen production. Calculated Bader charge and Fermi energy level show that a built‐in electric field from BP to GCN forms in its interface. The energy barrier and built‐in electric field promote the recombination of photogenerated electrons in GCN conduction band and photogenerated holes in BP valence band; electrons on the BP conduction band and holes on the GCN valence band are effectively separated in space; and more electrons and holes can participate in redox reactions on the surface. The BP/GCN heterojunction is a type Z heterojunction. Significant improvement in photocatalytic reaction efficiency is attributed to the type Z photocatalytic mechanism and small free energy of hydrogen adsorption. Herein, it is aimed to offer insights into the photocatalytic mechanism of 2D/2D heterojunctions.

Hydrothermal-assisted synthesis of Co-doped ZnO nanoparticles catalyst for sodium borohydride dehydrogenation and photodegradation of organic pollutants in water

In recent years, studies on dye removal and hydrogen energy have gained momentum. However, these studies are still not in the desired position. Existing biological and physical methods for dye removal are quite inadequate. In hydrogen production, the efficiency is very low when a catalyst is not used. It is important to obtain inexpensive catalysts for both purposes. For this purpose, Cobalt doped Zinc oxide nanoparticles (Co-doped ZnO NPs) were synthesized using a one-pot flash combustion approach. The photocatalytic activity and hydrolysis process of the produced catalyst on NaBH4 were evaluated. The photocatalytic activity of Co-doped ZnO NPs was investigated for decolorization against certain dyes under sunlight irradiation. Co-doped ZnO NPs were analyzed for hydrogen production from NaBH4 hydrolysis. It has been determined that the nanomaterial has a superior catalytic activity with Turnover frequency (TOF) of 1682.3 min−1, 32.45 kJ/mol enthalpy (∆E),-158.4 J/mol.K entropy (∆S), and 34.94 kJ/mol activation energy (EA) obtained as a result of the hydrolysis reaction of Co-doped ZnO NPs. Their reusability was found to be 72.5% at the 4th cycle. The photocatalytic activity of the Co-doped ZnO NPs was found 81.22% (120 min) and 86.98% (90 min) against RhB and MB dyes, respectively. According to the results obtained, it has been seen that Co-doped ZnO NPs are reusable catalysts with high catalytic activity for hydrogen production as a clean energy source. At the same time, it was emphasized that a photocatalyst with high catalytic activity was obtained for wastewater treatment.

O-doped and nitrogen vacancies 3D C3N4 activation of peroxydisulfate for pollutants degradation and transfer hydrogenation of nitrophenols with water

A three-dimensional carbon nitride co-modified through oxygen doping and nitrogen vacancies was prepared via an ordinary hydrothermal and thermal polymerization reaction of dicyandiamide and polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer (PEPE-C3N4). The electronic structure of carbon and nitrogen was proven through solid-state nuclear magnetism and electron loss energy spectroscopy. Density functional theory calculations revealed reduced band gap and altered charge density. The results show that the PEPE-C3N4 constructed by O-doped and nitrogen vacancy released electrons to activate peroxodisulfate (PDS), in which the 1% PEPE-C3N4 in the photocatalytic PDS system showed about 12 and 30 times increase of the photodegradation of 2-mercaptobenzothiazole (MBT) and bisphenol A (BPA), respectively, compared to graphite-phase carbon nitride (g-C3N4). The degradation products of MBT and BPA were named according to applying liquid chromatography-mass spectrometry and conceivable degradation pathways proposed. Furthermore, 1% PEPE-C3N4 had the highest hydrogen production activity (8275.74 μmol•h−1•g−1); it completely hydrogenates 4-nitrophenol to 4-aminophenol after 2.5 h of simulated sunlight. Additionally, biomass was used instead of TEOA to measure the coupling operation of H2 generation and selective oxidation of 5-hydroxymethylfurfural (HMF) to 2, 5-furandicarboxaldehyde (DFF). The optimized PEPE-C3N4 demonstrated high efficiency for selective oxidation of HMF to DFF with simultaneous H2 co-production (1176.84 μmol•h−1•g−1 for H2 and 357.67 μmol•h−1•g−1 for DFF), 5.31 and 2.36 times more excellent than that of g-C3N4, respectively. This study outlines a way to devise photocatalysts for organic pollutant degradation and biomass value-added co-production of hydrogen.

An efficient electron donor containing a silicon heteroatom for organic photocatalysts with high hydrogen production activity.

We report here 4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene (SiDT) as an electron donor to construct a donor-acceptor type conjugated polymer (PSiDT-BTDO) photocatalyst with a narrow band gap by employing dibenzo[b,d]thiophene-S,S-dioxide as an electron acceptor. The resulting polymer PSiDT-BTDO could realize a high hydrogen evolution rate of 72.20 mmol h-1 g-1 under ultraviolet-visible light with a Pt co-catalyst, due to the enhanced hydrophilicity as well as the decreased recombination rate of photo-induced holes/electrons and the dihedral angles of the polymer chains. The high photocatalytic activity of PSiDT-BTDO reveals the promising application of the SiDT donor in designing high-performance organic photocatalysts for hydrogen evolution.

Porous Ni3Fe intermetallic compounds as efficient and stable catalysts for the hydrogen evolution reaction in alkaline solutions.

It is crucial to develop cost-effective novel non-noble metal catalysts with high activity and durability for large-scale industrial hydrogen production via water splitting. Here, based on a facile powder metallurgy method, Ni3Fe intermetallic electrodes with porous structures and controllable phases have been designed and fabricated by sintering mixed Ni and Fe powders under an Ar atmosphere. The effects of sintering temperature on the morphology, porous structure and phase composition of the intermetallic were studied. The resultant Ni3Fe-900 intermetallic electrode exhibits promising HER activity in alkaline electrolytes with an overpotential of 112 mV to drive a current density of 10 mA cm-2. Additionally, the Ni3Fe-900 intermetallic electrode shows good alkali corrosion resistance and stability in the HER process at a current density as high as 500 mA cm-2 for 24 h with no significant changes of the surface morphology, porous structure and phases. The efficient HER performance of the Ni3Fe-900 electrode is attributed to the unique intrinsic activity of the intermetallic electrode, increased accessible active sites originating from the porous structure and accelerated charge transfer. This work provides new insights into the design of electrocatalysts for industrial large-scale hydrogen production by water splitting.

A novel direct Z-scheme heterojunction of CoTiO3/ZnIn2S4 for enhanced photocatalytic H2 evolution activity

The shortage of fossil energy has become a growing global concern. It is particularly important to make full use of the infinite solar energy resources, and transform them into sustainable and clean energy. The development of hydrogen energy has become a feasible solution to solve the energy shortage problem. The preparation of photocatalysts featuring efficient charge transfer channels and high hydrogen production activity provides a pathway for the development of hydrogen energy. In this paper, we report for the first time the direct assembly of 2D ZnIn2S4 (ZIS) nanosheets on the surface of CoTiO3 (CTO). The synthesized CoTiO3/ZnIn2S4 (CTO/ZIS) photocatalyst features a direct Z-scheme charge transfer channel, which enhances the separation rate of photogenerated carriers, and accelerates the photocatalytic H2 evolution (PHE) rate. Without the assistance of any co-catalyst, the PHE rate of prepared CoTiO3/ZnIn2S4 was as high as 5.21 mmol g−1 h−1. Moreover, the H2 evolution rate of CoTiO3/ZnIn2S4 almost did not decrease significantly after four consecutive 4 h cycles. This investigation provides a valuable approach for the exploitation of novel and efficient Z-scheme photocatalysts in the application of solar energy to hydrogen energy conversion.

CdSe-Decorated Flowerlike CaMoO4 Microspheres with Enhanced Hydrogen Production Activity.

Photocatalytic hydrogen production technology from water is a more effective and promising method to solve energy and environmental crises. In this work, flowerlike CaMoO4 microspheres were successfully synthesized by an ultrasonic precipitation method and modified with variable concentrations of CdSe NCs. CdSe/CaMoO4 microspheres showed increased light absorption ability, larger relative surface area, lower electrochemical impedance, and longer fluorescence lifetime. The photocatalytic hydrogen production rate of CdSe/CaMoO4 microspheres could reach up to 10 162.33 μmol g-1 h-1. The constructed type-I heterostructure improved the separation of photogenerated electrons and inhibited the rapid recombination of photogenerated electrons and holes, thus enhancing the photocatalytic hydrogen production performance. CdSe/CaMoO4 with high hydrogen production activity would be an efficient photocatalyst for hydrogen production applications.

Amorphization-crystallization synergism on MoSx homojunction for boosting photocatalytic H2 production of TiO2 in alkaline medium

Low-cost molybdenum sulfide (MoS2) has been widely regarded as a potential H2-production cocatalyst for various photocatalysts. However, compared with neutral or acidic medium, MoS2 cocatalyst generally exhibits a very limited H2-production activity in alkaline medium owing to the complex progress, including the H2O adsorption and activation, OH desorption and evolution of hydrogen. In this study, an amorphous-crystalline MoSx homojunction (ac-MoSx) is synthesized and anchored on TiO2 surface to greatly enhance its photocatalytic hydrogen production efficiency in alkaline medium. Herein, the ratio of amorphous to crystalline MoSx phase in the ac-MoSx homojunction can be regulated by controlling the calcination temperature (100–700 °C). Photocatalytic results show that the resultant ac-MoSx/TiO2(300 °C) has the highest hydrogen-production activity (3.43 mmol h−1 g−1, AQE = 16.3 %) in alkaline medium, which is higher compared to that of a-MoSx/TiO2 by 4 times. An amorphization-crystallization synergism of MoSx homojunction was proposed for the improved photocatalytic hydrogen-production activity of TiO2 in alkaline medium, where the Mo atom of crystalline MoS2 can act as the excellent water-activation site, while the unsaturated S atom of amorphous MoSx works as the outstanding H2-evolution active center. This work offers a new and innovative strategy to construct highly-active alkaline H2-production catalysts in photocatalysis and electrochemistry fields.

Modulation the electronic structure of hollow structured CuO-NiCo2O4 nanosphere for enhanced catalytic activity towards methanolysis of ammonia borane

Rational construction of cost-efficient catalysts with high activity and durability for hydrogen production from ammonia borane (AB) methanolysis is highly desirable but remains a substantial challenge. In this work, we constructed a series of non-noble-metal based hollow CuO-NiCo2O4 nanospheres composite, in which the CuO-NiCo2O4-0.8 nanospheres exhibit robust catalytic activity with a high turnover frequency (TOF) of 23.2 molH2 molcat.−1 min−1 towards AB methanolysis. Systemic experimental and computational studies reveal the promotion of activity results from the synergistic effect between CuO and NiCo2O4. It is revealed the combination of CuO with NiCo2O4 caused the electrons migration among Cu, Ni and Co sites and the change of d-band centers of catalyst, thus enhancing the adsorption process of CH3OH and AB molecules on catalyst and subsequently promoting the catalytic activity. Moreover, the Co center in CuO-NiCo2O4 composite is recognized as active sites by DFT calculations. Mechanistically, the rate determining step is the dissociation of OH bond in CH3OH, which is confirmed by kinetic isotopic effect experiment. A plausible mechanism of methanolytic dehydrogenation of AB on CuO-NiCo2O4 was proposed based on experiment and DFT calculations. These findings should shed light on the rational construction of cost-efficient catalysts with high performance for hydrogen production from AB methanolysis.

2D black NiO with oxygen vacancies/1D CdS nanocomposites for efficient visible-light-driven photocatalytic H2 production

Constructing highly active and stable earth-abundant heterojunction to replace expensive metals is regarded as an effective strategy in the photocatalytic H2 production system. Herein, a NiO with oxygen vacancies and broad absorption in the visible light band is prepared and the introduction of oxygen vacancies leads to the enhancement of catalytic activity and electrical conductivity of NiO. Meanwhile, a 2D NiO/1D CdS heterojunction is constructed in different atmospheres for photocatalytic H2 production. Different calcination atmospheres will result in distinct surface components, which further brings about a vast difference in activity. The best NiO/CdS catalyst calcined in Ar flow shows a dramatic Hydrogen evolution rate of 15.6 mmol·g−1·h−1 under visible light irradiation, which is comparable to CdS with photo-deposited palladium. The apparent quantum efficiency exceeded 15 % under visible light at 420 nm and 475 nm. Further investigation with contact potential differences (CPD) and in-situ Kelvin probe force microscopy (KPFM) technology indicates the dynamic process of photogenerated carrier transfer from CdS to NiO under illumination, which explains the reason for the high-efficiency utilization of photogenerated charge and high hydrogen production activity.

Construction of 0D/2D Schottky Heterojunctions of ZnO and Ti3C2 Nanosheets with the Enriched Transfer of Interfacial Charges for Photocatalytic Hydrogen Evolution.

The development of cost-effective co-catalysts of high photocatalytic activity and recyclability is still a challenge in the energy transformation domain. In this study, 0D/2D Schottky heterojunctions, consisting of 0D ZnO and 2D Ti3C2, were successfully synthesized by the electrostatic self-assembling of ZnO nanoparticles on Ti3C2 nanosheets. In constructing these heterojunctions, Ti3C2 nanosheets acted as a co-catalyst for enhancing the transfer of excitons and their separation to support the photocatalytic response of ZnO. The as-prepared ZnO/Ti3C2 composites demonstrate an abbreviated charge transit channel, a huge interfacial contact area and the interfacial electrons’ transport potential. The extended optical response and large reactive area of the ZnO/Ti3C2 composite promoted the formation of excitons and reactive sites on the photocatalyst’s surface. The ZnO/Ti3C2 Schottky heterojunction showed significantly high photocatalytic activity for hydrogen production from a water–ethanol solution under the light illumination in the visible region. The hydrogen evolution overoptimized the ZnO/Ti3C2 composition with 30 wt.% of Ti3C2, which was eight times higher than the pristine ZnO. These findings can be helpful in developing 0D/2D heterojunction systems for photocatalytic applications by utilizing Ti3C2 as a low-cost co-catalyst.

A novel electrocatalytic system with high reactive chlorine species utilization capacity to degrade tetracycline in marine aquaculture wastewater

The problems of high salinity and coexistence of antibiotics in mariculture wastewater pose a great challenge to the traditional wastewater treatment technology. Herein, an electrocatalytic system based on cathodes to sustain reactive chlorine species (RCS) in a high chlorine environment was proposed. The results show that the content of RCS is affected by cathodes. The electrocatalytic system with FeNi/NF as cathode has the largest RCS retention capacity when compared with other cathode systems (carbon felt, nickel foam, copper foam, stainless steel, and nickel-iron foam). This is related to FeNi/NF's higher hydrogen production activity, which inhibits the reduction reaction of RCS. Furthermore, the degradation of tetracycline by the proposed FeNi/NF system maintained long-term effective performance across 20 cycles. Thus, the application of high chlorine resistance electrocatalysis system provides a possibility for practical electrocatalysis treatment of mariculture wastewater.