Synergistic Contribution of Oligo(ethylene glycol) and Fluorine Substitution of Conjugated Polymer Photocatalysts toward Solar Driven Sacrificial Hydrogen Evolution

To separately explore the importance of hydrophilicity and backbone planarity of polymer photocatalyst, a series of benzothiadiazole-based donor–acceptor alternating copolymers incorporating alkoxy, linear oligo(ethylene glycol) (OEG) side chain, and backbone fluorine substituents is presented. The OEG side chains in the polymer backbone increase the surface energy of the polymer nanoparticles, thereby improving the interaction with water and facilitating electron transfer to water. Moreover, the OEG-attached copolymers exhibit enhanced intermolecular packing compared to polymers with alkoxy side chains, which is possibly attributed to the self-assembly properties of the side chains. Fluorine substituents on the polymer backbone produce highly ordered lamellar stacks with distinct π–π stacking features; subsequently, the long-lived polarons toward hydrogen evolution are observed by transient absorption spectroscopy. In addition, a new nanoparticle synthesis strategy using a methanol/water mixed solvent is first adopted, thereby avoiding the screening effect of surfactants between the nanoparticles and water. Finally, hydrogen evolution rate of 26 000 µmol g⁻¹ h⁻¹ is obtained for the copolymer incorporated with both OEG side chains and fluorine substituents under visible-light irradiation (λ > 420 nm). This study demonstrates how the glycol side chain strategy can be further optimized for polymer photocatalysts by controlling the backbone planarity.     

The Precision Defect Engineering with Nonmetallic Element Refilling Strategy in g-C3N4 for Enhanced Photocatalytic Hydrogen Production

Traditional defect engineering and doping strategies are considered effective means for improving H₂ evolution, but the uncontrollability of the modification process does not always lead to efficient activity. A defect-induced heteroatom refilling strategy is used here to synthesize heteroatoms introduced carbon nitride by precisely controlling the “introduction” sites on efficient N1 sites. Density functional theory calculations show that the refilling of B, P, and S sites have stronger H₂O adsorption and dissociation capacity than traditional doping, which makes it an optimal H₂ production path. The large internal electric field strength of heteroatom-refilled catalysts leads to fast electron transfer and the hydrogen production of the best sample is up to 20.9 mmol g⁻¹ h⁻¹. This work provides a reliable and clear insight into controlled defect engineering of photocatalysts and a universal modification strategy for typical heteroatom and co-catalyst systems for H₂ production.     

NiS/Cd0.6Zn0.4S Schottky Junction Bifunctional Photocatalyst for Sunlight-Driven Highly Selective Catalytic Oxidation of Vanillyl Alcohol Towards Vanillin Coupled with Hydrogen Evolution Reaction

Selective oxidation of biomass-based molecules to high-value chemicals in conjunction with hydrogen evolution reaction (HER) is an innovative photocatalysis strategy. The key challenge is to design bifunctional photocatalysts with suitable band structures, which can achieve highly efficient generation of high-value chemicals and hydrogen. Herein, NiS/Cd_0.6Zn_0.4S Schottky junction bifunctional catalysts are constructed for sunlight-driven catalytic vanillyl alcohol (VAL) selective oxidation towards vanillin (VN) coupling HER. At optimal conditions, the 8% NiS/Cd_0.6Zn_0.4S photocatalyst achieves high activity of VN production (3.75 mmol g⁻¹ h⁻¹) and HER (3.84 mmol g⁻¹ h⁻¹). It also exhibits remarkable VAL conversion (66.9%), VN yield (52.1%), and selectivity (77.8%). The photocatalytic oxidation of VAL proceeds a carbon-centered radical mechanism via the cleavage of α_C–H bond. Experimental results and theoretical calculations show that NiS with metallic properties enhances the electron transfer capability. Importantly, a Ni-S-Cd “electron bridge” formed at the interface of NiS/Cd_0.6Zn_0.4S further improves the separation/transfer of electrone/h⁺ pairs and also furnishes HER active sites due to its smaller the |ΔG_H*| value, thereby resulting in a remarkably HER activity. This work sheds new light on the selective catalytic oxidation VAL to VN coupling HER, with a new pathway towards achieving its efficient HER efficiency.     

Unlocking the catalytic activities of 2H-phase Mo-based compounds via topological conversion reaction

Although 2H molybdenum disulfide (MoS₂) layers are highly desirable for hydrogen evolution reaction (HER) owing to their high chemical stabilities and low cost, the inert basal plane and semiconducting nature severely hinder their practical applications. Here, the catalytic activities of 2H phase molybdenum-based compounds are unlocked via topological conversion reaction from Mo₂GeC MAX phase to accordion-like molybdenum phosphosulphide. During the conversion reaction, phosphorus atoms can be implanted into the sandwich-like S-Mo-S planes and gradually substitute sulfur atoms, which are beneficial to optimize the electronic configuration and facilitate to absorb water molecules, unlocking the inert basal planes of 2H phase molybdenum-based compounds. The accordion-like molybdenum phosphosulphide exhibits high hydrogen production rates up to 288 mmol g⁻¹ h⁻¹ cm⁻² at a high loading of 3 mg cm⁻² and ultralong durability up to 35,000 cycles, satisfying the practical application for HER.     

Self-Supported Pd Nanorod Arrays for High-Efficient Nitrate Electroreduction to Ammonia

Electrochemical nitrate (NO₃⁻) reduction to ammonia (NH₃) offers a promising pathway to recover NO₃⁻ pollutants from industrial wastewater that can balance the nitrogen cycle and sustainable green NH₃ production. However, the efficiency of electrocatalytic NO₃⁻ reduction to NH₃ synthesis remains low for most of electrocatalysts due to complex reaction processes and severe hydrogen precipitation reaction. Herein, high performance of nitrate reduction reaction (NO₃⁻RR) is demonstrated on self-supported Pd nanorod arrays in porous nickel framework foam (Pd/NF). It provides a lot of active sites for H* adsorption and NO₃⁻ activation leading to a remarkable NH₃ yield rate of 1.52 mmol cm⁻² h⁻¹ and a Faradaic efficiency of 78% at −1.4 V versus RHE. Notably, it maintains a high NH₃ yield rate over 50 cycles in 25 h showing good stability. Remarkably, large-area Pd/NF electrode (25 cm²) shows a NH₃ yield of 174.25 mg h⁻¹, be promising candidate for large-area device for industrial application. In situ FTIR spectroscopy and density functional theory calculations analysis confirm that the enrichment effect of Pd nanorods encourages the adsorption of H species for ammonia synthesis following a hydrogenation mechanism. This work brings a useful strategy for designing NO₃⁻RR catalysts of nanorod arrays with customizable compositions.     

Hierarchical Nanospheres with Polycrystalline Ir&Cu and Amorphous Cu2O toward Energy-Efficient Nitrate Electrolysis to Ammonia

Electrochemical reduction reaction of nitrate (NITRR) provides a sustainable route toward the green synthesis of ammonia. Nevertheless, it remains challenging to achieve high-performance electrocatalysts for NITRR especially at low overpotentials. In this work, hierarchical nanospheres consisting of polycrystalline Iridium&copper (Ir&Cu) and amorphous Cu₂O (Cu_xIr_yO_z NS) have been fabricated. The optimal species Cu_0.86Ir_0.14O_z delivers excellent catalytic performance with a desirable NH₃ yield rate (YR) up to 0.423 mmol h⁻¹ cm⁻² (or 4.8 mg h⁻¹ mg_cat⁻¹) and a high NH₃ Faradaic efficiency (FE) over 90% at a low overpotential of 0.69 V (or 0 V_RHE), where hydrogen evolution reaction (HER) is almost negligible. The electrolyzer toward NITRR and hydrazine oxidation (HzOR) is constructed for the first time with an electrode pair of Cu_0.86Ir_0.14O_z//Cu_0.86Ir_0.14O_z, yielding a high energy efficiency (EE) up to 87%. Density functional theory (DFT) calculations demonstrate that the dispersed Ir atom provides active site that not only promotes the NO₃⁻ adsorption but also modulates the H adsorption/desorption to facilitate the proton supply for the hydrogenation of *N, hence boosting the NITRR. This work thus points to the importance of both morphological/structural and compositional engineering for achieving the highly efficient catalysts toward NITRR.     

Energy Storage Application of Conducting Polymers Featuring Dual Acceptors: Exploring Conjugation and Flexible Chain Length Effects

Solution-processable conducting polymers (CPs) are a compelling alternative to inorganic counterparts because of their potential for tuning chemical properties and creating flexible organic electronics. CPs, which typically comprise either only an electron donor (D) or its alternative combinations with an electron acceptor (A), exhibit charge transfer behavior between the units, resulting in an electrical conductivity suitable for utilization in electronic devices and for energy storage applications. However, the energy storage behavior of CPs with a sequence of electron acceptors (A–A), has rarely been investigated, despite their promising lower band gap and higher charge carrier mobility. Utilizing the aforesaid concept herein, four CPs featuring benzodithiophenedione (BDD), and diketopyrrolepyrrole (DPP) are synthesized. Among them, the BDDTH-DPPEH polymer exhibited the highest specific capacitance of 126.5 F g⁻¹ at a current density of 0.5 A g⁻¹ in an organic electrolyte over a wide potential window of −0.6–1.4 V. Notably, the supercapacitor properties of the polymeric electrode materials improved with increasing conjugation length by adding thiophene donor units and shortening the alkyl chain lengths. Furthermore, a symmetric supercapacitor device fabricated using BDDTH-DPPEH exhibited a high-power density of 4000 W kg⁻¹ and an energy density of 31.66 Wh kg⁻¹.     

Utilizing Metal-Thiocatecholate Functionalized UiO-66 Framework for Photocatalytic Hydrogen Evolution Reaction

Exploiting clean energy is essential for sustainable development and sunlight-driven photocatalytic water splitting represents one of the most promising approaches toward this goal. Metal-organic frameworks (MOFs) are competent photocatalysts owing to their tailorable functionality, well-defined structure, and high porosity. Yet, the introduction of the unambiguous metal-centered active site into MOFs is still challenging since framework motifs capable of anchoring metal ions firmly are lacking. Herein, the assembly using 1,4-dicarboxylbenzene-2,3-dithiol (H₂ dcbdt ) and Zr-Oxo clusters to give a thiol-functionalized UiO-66 type framework,  UiO-66-dcbdt, is reported. The thiocatechols on the struts are allowed to capture transition metal (TM) ions to generate  UiO-66-dcbdt-M  ( M   = Fe, Ni, Cu) with unambiguous metal-thiocatecholate moieties for photocatalytic hydrogen evolution reaction (HER).  UiO-66-dcbdt-Cu  is found the best catalyst exhibiting an HER rate of 4.18 mmol g⁻¹ h⁻¹ upon irradiation with photosensitizing Ru-polypyridyl complex. To skip the use of the external sensitizer,  UiO-66-dcbdt-Cu  is heterojunctioned with titanium dioxide (TiO₂) and achieves an HER rate of 12.63 mmol g⁻¹ h⁻¹ (32.3 times that of primitive TiO₂). This work represents the first example of MOF assembly employing H₂ dcbdt  as the mere linker followed by chelation with TM ions and undoubtedly fuels the rational design of MOF photocatalysts bearing well-defined active sites.     

Covalent Pyrimidine Frameworks via a Tandem Polycondensation Method for Photocatalytic Hydrogen Production and Proton Conduction

The development of heteroaromatic conjugated porous polymers (H-CPPs) have received enormous research interests, because of the important functional roles of the heteroatoms in photocatalysis and proton conduction. However, due to the synthetic challenges deriving from the stable structures, the structural diversity and synthetic methods of them are still limited. Herein, a new type of H-CPPs, covalent pyrimidine frameworks (CPFs), via an efficient tandem polycondensation reaction between aldehyde, acetyl, and amidine monomers is reported. The resulting CPFs are bridged by pyrimidine units, rich of nitrogen atoms and can be structurally regulated on demand. The CPFs are shown to be active photocatalysts for hydrogen evolution from methanol via a photo-thermo-catalysis process, achieving an excellent hydrogen evolution rate of 5282.8 µmol h⁻¹ g⁻¹. The CPFs can be further processed into a mixed matrix membrane, displaying an excellent proton conductivity of 1.30 × 10⁻² S cm⁻¹ at 413 K under anhydrous condition.     

In-situ synthesized and photocatalytic performance evaluation of MoS2-C-g-C3N4 heterostructure photocatalyts

The heterostructure between two semiconductor materials that had suitable band edge positions can contribute to the separation of photoelectrons and holes. In this paper, the heterostructure MoS₂-C-g-C₃N₄ photocatalysts were in-situ synthesized at one-pot high temperature processing. The obtained 0.4 MoS₂-C-g-C₃N₄ composites displayed the highest photocatalytic hydrogen evolution activity with a corresponding H₂ evolution rate of 238 μmol g⁻¹h⁻¹, which was about 4.5 times higher than that of 3% C-g-C₃N₄, and the photocatalyts exhibited excellent stability which was used for photocatalytic hydrogen evolution reaction for 12 h. The 0.4 MoS₂-C-g-C₃N₄ sample displayed well degradation activities for MO, MB, RhB, MR and Ar18, and the scavenging studies indicated the major involvement of ·O₂^– radicals in the degradation process. The enhanced photocatalytic activity of MoS₂-C-g-C₃N₄ composite was predominantly attributed to the synergistic effects of type II heterostructure between g-C₃N₄ and MoS₂, which effectively accelerated the transfer and separation of photogenerated charge carriers. Besides, the introduction of noble metal-free MoS₂ co-catalyst further improved visible light absorption and provided more active sites for H₂ evolution reaction. Such work is promising for designing a novel heterostructure photocatalysts for solar-to-fuel conversion and environmental modification.     

Mesoporous Polymeric Cyanamide‐Triazole‐Heptazine Photocatalysts for Highly‐Efficient Water Splitting

Conjugated polymers are promising light harvesters for water reduction/oxidation due to their simple synthesis and adjustable bandgap. Herein, both cyanamide and triazole functional groups are first incorporated into a heptazine‐based carbon nitride (CN) polymer, resulting in a mesoporous conjugated cyanamide‐triazole‐heptazine polymer (CTHP) with different compositions by increasing the quantity of cyanamide/triazole units in the CN backbone. Varying the compositions of CTHP modulates its electronic structures, mesoporous morphologies, and redox energies, resulting in a significantly improved photocatalytic performance for both H₂ and O₂ evolution under visible light irradiation. A remarkable H₂ evolution rate of 12723 µmol h^?1 g^?1 is observed, resulting in a high apparent quantum yield of 11.97% at 400 nm. In parallel, the optimized photocatalyst also exhibits an O₂ evolution rate of 221 µmol h^?1 g^?1, 9.6 times higher than the CN counterpart, with the value being the highest among the reported CN‐based bifunctional photocatalysts. This work provides an efficient molecular engineering approach for the rational design of functional polymeric photocatalysts.     

Constructing Ru@C3N4/Cu Tandem Electrocatalyst with Dual-Active Sites for Enhanced Nitrate Electroreduction to Ammonia

Electroreduction of nitrate to ammonia reaction (NO₃⁻RR) is considered as a promising carbon-free energy technique, which can eliminate nitrate from waste-water also produce value-added ammonia. However, it remains a challenge for achieving satisfied ammonia selectivity and Faraday efficiency (FE) due to the complex multiple-electron reduction process. Herein, a novel Tandem electrocatalyst that Ru dispersed on the porous graphitized C₃N₄ (g-C₃N₄) encapsulated with self-supported Cu nanowires (denoted as Ru@C₃N₄/Cu) for NO₃⁻RR is presented. As expected, a high ammonia yield of 0.249 mmol h⁻¹ cm⁻² at −0.9 V and high FE_NH3 of 91.3% at −0.8 V versus RHE can be obtained, while achieving excellent nitrate conversion (96.1%) and ammonia selectivity (91.4%) in neutral solution. In addition, density functional theory (DFT) calculations further demonstrate that the superior NO₃⁻RR performance is mainly resulted from the synergistic effect between the Ru and Cu dual-active sites, which can significantly enhance the adsorption of NO₃⁻ and facilitate hydrogenation, as well as suppress the hydrogen evolution reaction, thus lead to highly improved NO₃⁻RR performances. This novel design strategy would pave a feasible avenue for the development of advanced NO₃⁻RR electrocatalysts.     

Yolk-shell CdS@void@TiO2 composite particles with photocorrosion resistance for enhanced dye removal and hydrogen evolution

Yolk-shell CdS@void@TiO₂ (cadmium sulfide@void@titanium dioxide) composite particles (CPs), consisting of three parts: core (CdS) synthesized by solvent thermal reaction, void generated by polypyrrole (PPy) sacrificed layers and porous shell (TiO₂) by sol-gel method, were innovatively fabricated. The actual yolk-shell structure and chemical composition of the resultant CdS@void@TiO₂ were verified by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction analyses (XRD), and X-ray photoelectron spectroscopy (XPS). CdS@void@TiO₂ CPs possessed enhanced visible light response due to its narrower energy gap (2.9 eV) than TiO₂ (3.2 eV). With the support of photocatalytic performance test results, CdS@void@TiO₂ exhibits much higher hydrogen evolution rate up to 1893.5 μmol h⁻¹ g⁻¹ as well as dye removal efficiency both under visible and UV light irradiation than pristine TiO₂. The covering of TiO₂ shell remarkably promotes the photocorrosion resistance of CdS. The unique yolk-shell structure promotes striking photocatalytic performance in dye removal and hydrogen evolution. A possible photocatalytic mechanism about enhanced photocatalytic activity and robust photostability is also proposed.     

Oxygenated Triazine-Heptazine Heterostructure Creates an Enormous Ascension to the Visible Light Photocatalytic Hydrogen Evolution Performance of Porous C3N4 Nanosheets

A highly efficient g-C₃N₄ photocatalyst is developed by a novel one-pot thermal polymerization method under a salt fog environment generated by heating the aqueous solution of urea and mixed metal salts of NaCl/KCl, namely SF-CN. Thanks to the synergistic effect of the oxygenation and chemical etching of the salt fog, the obtained SF-CN is an oxygenated ultrathin porous carbon nitride with an intermolecular triazine-heptazine heterostructure, meanwhile, shows enlarged specific surface area, greatly enhanced absorption of visible light, narrowed band gap with a lower conduction band, and an increased photocurrent response due to the effective separation of photogenerated holes and electrons, comparing to those of pristine g-C₃N₄. The theoretical simulations further reveal that the triazine-heptazine heterostructure possesses better photocatalytic hydrogen evolution (PHE) capability than pure triazine and heptazine carbon nitrides. In turn, SF-CN demonstrates an excellent visible light PHE rate of 18.13 mmol h⁻¹ g⁻¹, up to 259.00 times of that of pristine g-C₃N₄.     

Photocatalytic hydrogen evolution over surface-modified titanate nanotubes by 5-aminosalicylic acid decorated with silver nanoparticles

The efficiency of titanate-nanotubes-based photocatalysts towards hydrogen production was studied in the presence of the sacrificial agent, 2-propanol. The highest hydrogen production rate (~120 μmol h⁻¹ g⁻¹) was observed over surface-modified titanate nanotubes by 5-amino salicylic acid decorated with nanometer-sized silver nanoparticles. The X-ray diffraction analysis, transmission electron microscopy, nitrogen adsorption–desorption isotherms, and diffuse reflection spectroscopy were applied to characterize the prepared photocatalytic materials. The better photocatalytic performance of inorganic–organic hybrid materials in comparison to the pristine titanate nanotubes is a consequence of their improved light-harvesting ability due to the formation of interfacial charge transfer (ICT) complex, as well as the presence of metallic silver nanoparticles that suppress the recombination of photo-generated charge carriers. The spin trapping EPR experiments under irradiation of prepared photocatalysts with either UV or visible light were used to monitor the appearance of hydroxyl radicals and superoxide radical anions. The generation of superoxide radical anions under visible light irradiation was detected for hybrid materials, but not for the pristine titanate nanotubes. These results are a consequence of enhanced promotion of electrons to the conduction band due to extended absorption in visible spectral range in hybrids and support the higher efficiency of hydrogen generation observed for surface-modified titanate nanotubes by 5-amino salicylic acid decorated with silver nanoparticles.     

Dinitrogen Reduction Coupled with Methanol Oxidation for Low Overpotential Electrochemical NH3 Synthesis Over Cobalt Pyrophosphate as Bifunctional Catalyst

Electrochemical dinitrogen (N₂) reduction to ammonia (NH₃) coupled with methanol electro-oxidation is presented in the current work. Here, methanol oxidation reaction (MOR) is proposed as an alternative anode reaction to oxygen evolution reaction (OER) to accomplish electrons-induced reduction of N₂ to NH₃ at cathode and oxidation of methanol at anode in alkaline media thereby reducing the overall cell voltage for ammonia production. Cobalt pyrophosphate micro-flowers assembled by nanosheets are synthesized via a surfactant-assisted sonochemical approach. By virtue of structural and morphological advantages, the maximum Faradaic efficiency of 43.37% and NH₃ yield rate of 159.6 µg h⁻¹ mg_ca⁻¹ is achieved at a potential of −0.2 V versus RHE. The proposed catalyst is shown to also exhibit a very high activity (100 mA mg⁻¹ at 1.48 V), durability (2 h) and production of value-added formic acid at anode (2.78 µmol h⁻¹ mg_cat⁻¹ and F.E. of 59.2%). The overall NH₃ synthesis is achieved at a reduced cell voltage of 1.6 V (200 mV less than NRR-OER coupled NH₃ synthesis) when OER at anode is replaced with MOR and a high NH₃ yield rate of 95.2 µg h⁻¹ mg_cat⁻¹ and HCOOH formation rate of 2.53 µmol h⁻¹ mg⁻¹ are witnessed under full-cell conditions.     

Enhanced C?O Functionality on Carbon Papers Ensures Lowering Nucleation Delay of ALD for Ru towards Unprecedented Alkaline HER Activity

The success in lowering the nucleation delay for Atomic Layer Deposition (ALD) of Ru on carbon surfaces is mitigated by constructive pretreatments resulting enhancement of C O functionality. Treatment of the carbon papers (CP) allowed Ru species deposition for minimum number of ALD cycles (25 cycles) with good conformality. The development of electrocatalysts from single atoms to nanoparticles (NPs) on conductive supports with low metal loadings, thus improving performance, is essential in electrocatalysis. For alkaline hydrogen evolution reaction, ALD decorated CPs with Ru exhibit low onset potentials of ≈4.7 mV versus reversable hydrogen electrode (RHE) (at 10 mA cm⁻²) and a high turnover frequency of 1.92 H₂ s⁻¹ at 30 mV versus RHE. The Ru decorated CPs show comparable to higher catalytic activity than of Platinum (Pt) decorated CP also developed by ALD. The current representation of unfamiliar catalytic activities of Ru active centers developed by ALD, pave a bright and sustainable path for energy conversion reactions.     

Spontaneous Desaturation of the Solvation Sheath for High-Performance Anti-Freezing Zinc-Ion Gel-Electrolyte

In recent years, gel-electrolyte becomes pivotal in preventing hydrogen evolution, reducing dendrite growth, and protecting the zinc metal anode for zinc-ion batteries. Herein, a polyvinyl alcohol-based water–organic hybrid gel electrolyte with Agar and dimethyl sulfoxide is designed to construct the spontaneous desaturation of the solvation sheath for reducing hydrogen evolution and dendrite growth at room temperature and even low temperature. According to experimental characterization and theoretical calculations, the well binding between multihydroxy polymer and H₂O is achieved in the hybrid desaturated gel-electrolyte to regulate the inner and outer sheath. The ionic conductivity of hybrid gel-electrolyte reaches 7.4 mS cm⁻¹ even at −20 °C with only 0.5 m zinc trifluoromethanesulfonate (Zn(OTf)₂). The Zn symmetric cells cycle over 1200 h under 26 and −20 °C with improved mechanical properties and electrochemical performance. The asymmetric Zn || Cu cell with hybrid gel electrolyte reaches ≈99.02% efficiency after 250 cycles. The capacity of full cell is maintained at around 74 mAh g⁻¹ with almost unchanged retention rate from 50 to 300 cycles at −20 °C. This work provides an effective strategy for desaturated solvation to reach anti-freezing and high-density Zn energy storage devices.     

Green preparation of in-situ oxidized TiO2/Ti3C2 heterostructure for photocatalytic hydrogen production

The preparation of high-efficiency photocatalysts by green and mild methods is very attractive for photocatalysis field. Here, TiO₂/Ti₃C₂ was prepared by in-situ oxidation with a green method, in which only water or H₂O₂ was used. A heterojunction interface formed between the anatase phase TiO₂ and the Ti₃C_2, which was demonstrated by HRTEM and XRD. Fluorescence spectra and i-t transient photocurrent are used to study the separation efficiency of photogenerated electron-hole pairs. The close contact between Ti₃C₂ and TiO₂ speed up the separation of photo-generated electron-hole pairs, promoting a higher hydrogen production performance around 2520.4 μmol·g⁻¹·h⁻¹ on TCT-1.