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The activation capacity of molecular oxygen is an important indicator to evaluate the photocatalytic efficiency of photocatalysts. In this paper, WS2 nanosheet was deposited on hyper-crosslinked CTF-1-G (obtained by molecular expansion from covalent triazine framework CTF-1) to form a C-GW heterojunction, which promoted the photodegradation of pollutants and the activation of molecular oxygen. This novel C-GW heterojunction exhibited excellent degradation property for organic pollutants (tetracycline (TC), rhodamine B (RhB)) and activating molecular oxygen under visible light irradiation. Among them, C-GW15 could degrade 98% of 20 ppm TC in 60 min and 99% of 30 ppm RhB in 30 min, and it had the highest hydrogen generation rate and hydrogen production amount in 4 hours, which were 8.74 mmol h−1 g−1 and 34.94 mmol g−1, respectively. Meanwhile, C-GW15 had the strongest 3,3′,5,5′-tetramethylbenzidine oxidation capacity and could generate 1.83 μmol of ˙O2− in 60 min and the production of H2O2 was 20.8 μmol L−1 in 40 min. The results of this study clearly indicated that the combination of WS2 and CTF-1-G can enhance the visible light absorption capacity and photogenerated carrier separation efficiency, thus promoting the photocatalytic performance. Finally, a Z-type photocatalytic mechanism was proposed based on radical capture, molecular oxygen activation experiments and electron spin resonance analysis. These findings will extend the fundamental understanding of the Z-type photocatalytic mechanism and provide new opportunities for the rational design of CTF heterojunctions for the treatment of environmental pollution and clean energy conversion. [ABSTRACT FROM AUTHOR]

In this paper, a simple one-pot thermal synthesis method was used to successfully prepare Cu2+/biochar-doped TiO2 composite catalytic materials. The photocatalytic hydrogen production performance of the composites under different environmental conditions (dark, solar, and visible light irradiation) was analyzed in a biomass photocatalytic system using a corn straw suspension as a sacrificial agent. The Cu2+/biochar-doped TiO2 materials were characterized by SEM, TEM, XRD, FT-IR, XPS, and UV analysis. The photoelectric properties of the Cu2+/biochar-doped TiO2 composites were also analyzed, and the charge separation mechanism of photogenerated carriers under different environmental conditions was investigated. Compared with pure TiO2, the hydrogen production rate of Cu2+/biochar-doped TiO2 is 23.6 times higher under visible light irradiation and 16.8 times higher under simulated solar irradiation. Using density functional theory, a crystal structure model of Cu2+/biochar-doped TiO2 was established to analyze its energy band structure and density of states. An analysis of the mechanism shows that under simulated sunlight irradiation, the synergistic effect of the TiO2 doped with Cu2+ and biochar causes the formation of a potential Schottky heterojunction on the surface and induces interfacial charge transfer. Furthermore, under visible light irradiation, the photocatalytic production of hydrogen by the Cu2+/biochar-doped TiO2 composite is mainly due to the surface plasmon resonance mechanism of Cu ion-doped TiO2. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have great potential for producing photoelectrocatalyzed hydrogen and degrading pollutants, owing to several factors such as high porosity and tunable semiconductor-like properties. Wide band gaps, which restrict their use to only UV light induced reactions, and low efficiencies for the separation of photogenerated charge carriers (electrons and holes) pose significant challenges to the widespread applications of MOFs. In this study, a hierarchical hollow Pt@H-UiO-66-NH2/CdS ternary catalyst was designed and synthesized. The immobilized CdS nanoparticles (NPs) in this catalyst endow the MOF H-UiO-66-NH2 with high visible light absorption ability and the Pt NPs serve as electron sinks to improve charge carrier separation. Furthermore, the hierarchical hollow structure of H-UiO-66-NH2 in the composite contributes to boosting light absorption and shortening the distance for charge transfer. As a proof of principle, Pt@H-UiO-66-NH2/CdS catalyzes methylene blue (MB) degradation with a high rate constant of 1.025 × 10−2 and hydrogen production with a rate of 12 810 μmol g−1 h−1, the latter of which is about 2.3, 11.7 and 173 times higher than those of Pt@UiO-66-NH2/CdS, H-UiO-66-NH2/CdS and Pt@H-UiO-66-NH2, respectively. [ABSTRACT FROM AUTHOR]

Constructing heterostructures with efficient charge separation is a promising route to improve photocatalytic hydrogen production. In this paper, MoS x /CdS/KTaO 3 ternary heterojunction photocatalysts were successfully prepared by a two-step method (hydrothermal method and photo deposition method), which improved the photocatalytic hydrogen evolution activity. The results show that the rate of hydrogen evolution for the optimized photocatalyst is 2.697 mmol g−1·h−1under visible light, which is 17 times and 2.6 times of the original CdS (0.159 mmol g−1 h−1) and the optimal CdS/KTaO 3 (1.033 mmol g−1 h−1), respectively, and the ternary photocatalyst also shows good stability. The improvement on photocatalytic hydrogen evolution performance can be attributed to the formation of heterojunction between the prepared composite materials, which effectively promotes the separation and migration of photo-generated carriers. Amorphous MoS x acts as an electron trap to capture photogenerated electrons, providing active sites for proton reduction. This provides beneficial enlightenment for hydrogen production by efficiently utilizing sunlight to decompose water. • Successful preparation of a novel MoS x cocatalyst-modified CdS/KTO heterostructure without noble metals. • Composite catalysts exhibit excellent photocatalytic hydrogen evolution performance. • The hydrogen production rate of the composite is 17 times and 2.6 times that of pure CdS and CdS/KTO. • Amorphous MoS x acts as a trap to capture photogenerated electrons, providing active sites for proton reduction. [ABSTRACT FROM AUTHOR]

Photocatalytic processes offer promising solutions for environmental remediation and clean energy production, yet their efficiency under the visible light spectrum remains a significant challenge. Here, we report a novel silver–graphene (Ag-G) modified TiO2 (Ag-G-TiO2) nanocomposite photocatalyst that demonstrates remarkably enhanced photocatalytic activity for both dye wastewater degradation and hydrogen production under visible and UV light irradiation. Through comprehensive characterization and performance analysis, we reveal that the Ag-G modification narrows the TiO2 bandgap from 3.12 eV to 1.79 eV, enabling efficient visible light absorption. The nanocomposite achieves a peak hydrogen production rate of 191 μmolesg−1h−1 in deionized (DI) water dye solution under visible light, significantly outperforming unmodified TiO2. Intriguingly, we observe an inverse relationship between dye degradation efficiency and hydrogen production rates in dye solutions with tap water versus DI water, highlighting the critical role of water composition in photocatalytic processes. This work not only advances the understanding of fundamental photocatalytic mechanisms but also presents a promising photocatalyst for solar-driven environmental remediation and clean energy production. The Ag-G-TiO2 nanocomposite's enhanced performance across both visible and UV spectra, coupled with its dual functionality in dye degradation and hydrogen evolution, represents a significant step towards addressing critical challenges in water treatment and sustainable energy generation. Our findings highlight the complex interplay between light absorption and reaction conditions, offering new insights for optimizing photocatalytic systems. This research paves the way for developing more efficient and versatile photocatalysts, potentially contributing to the global transition towards sustainable technologies and circular economy in waste management and energy production. [ABSTRACT FROM AUTHOR]

A highly efficient, stable, easily recyclable carbon‐based [g‐C3N4/C]//[TiO2/C] Janus nanofibers heterostructure photocatalyst (gT‐JNHP) was first designed and constructed through the combination of conjugative electro‐spinning with subsequent calcination procedure. gT‐JNHP with novel Janus structure consists of two sides: one side is g‐C3N4/C nanofiber that absorbs visible light (VL), and the other side is TiO2/C nanofiber that can capture ultraviolet light (UL), and the two strands of nanofibers are tightly combined together to form the unique heterostructure Janus nanofiber, which can make full use of sunlight (SL). gT‐JNHP presents better remarkably boosted photocatalytic performance in comparison with the counterpart g‐C3N4/C, TiO2/C, or their mechanical mixture, and the degradation efficiencies of methylene blue in gT‐JNHP‐2, respectively, are 95.1% (160 min) and 98.6% (140 min), as well as hydrogen evolution rates reach up to 12.40 and 16.72 mmol h–1 g–1 under VL and simulated SL, respectively, thereby displaying the excellent dual functions of high‐efficient hydrogen release and removal of organic contaminant. The outstanding photocatalytic property is ascribed to the joint effect among the unique Janus‐typed heterostructure, catalyst components, and electrically conductive carbon fiber, achieving close contact between the interfaces, effective separation of photo‐excited carriers, strong light capture ability, and many more exposed active sites, etc. Feasible photocatalytic mechanisms are advanced. Moreover, gT‐JNHP owns the characteristics of flexible self‐standing, easy recycling, and superb durability. The constructing mechanisms of Janus nanofibers and gT‐JNHP are discussed in detail, and the novel fabricating techniques are established. The designing idea and construction techniques adopted in this paper are popularized for research and development of other peculiar uni‐dimensional dual‐functional nanofibrous photocatalysts. [ABSTRACT FROM AUTHOR]

In the field of photocatalysis, building a heterojunction is an effective way to promote electron transfer and enhance the reducibility of electrons. Herein, the S‐scheme heterojunction photocatalyst (CoS2/Zn0.5Cd0.5S) of CoS2 nanospheres modified Zn0.5Cd0.5S solid solution was synthesized and studied. The H2 evolution rate of the composite catalyst reached 25.15 mmol g−1 h−1, which was 3.26 times that of single Zn0.5Cd0.5S, whereas pure CoS2 showed almost no hydrogen production activity. Moreover, CoS2/Zn0.5Cd0.5S had excellent stability and the hydrogen production rate after six cycles of experiments only dropped by 6.19 %. In addition, photoluminescence spectroscopy and photoelectrochemical experiments had effectively proved that the photogenerated carrier transfer rate of CoS2/Zn0.5Cd0.5S was better than CoS2 or Zn0.5Cd0.5S single catalyst. In this study, the synthesized CoS2 and Zn0.5Cd0.5S were both n‐type semiconductors. After close contact, they followed an S‐scheme heterojunction electron transfer mechanism, which not only promoted the separation of their respective holes and electrons, but also retained a stronger reduction potential, thus promoting the reduction of H+ protons in photocatalytic experiments. In short, this work provided a new basis for the construction of S‐scheme heterojunction in addition to being used for photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

Black phosphorus (BP) has recently emerged as a versatile photocatalyst owing to its unique photophysical properties and tunable bandgap. Nonetheless, the rapid recombination of the photogenerated charges of pristine BP samples has significantly hindered its practical applications in photocatalysis. Herein, we report, for the first time, the effect of transition metal nanoparticles (Ni and Co) as co-catalysts on the photocatalytic activity of BP/tungsten disulfide (WS2) binary heterojunctions (BP/WS2-TM (TM: Ni, Co)) in the hydrogen evolution reaction (HER) under visible light irradiation (λ > 420 nm). Ternary heterojunctions named BP/WS2-TM (TM: Ni, Co) were synthesized via a chemical reduction method, leading to the formation of an S-scheme heterojunction, in which BP acts as a reduction catalyst and WS2 serves as an oxidation catalyst. BP/WS2-Ni and BP/WS2-Co performed substantial amounts of hydrogen generation of 9.53 mmol h−1g−1 and 12.13 mmol h−1g−1, respectively. Moreover, BP/WS2-Co exhibited about 5 and 15 times higher photocatalytic activity compared to the binary BP/WS2 heterojunctions and pristine BP, respectively. The enhanced photocatalytic activity of the heterojunction catalysts is attributed to the extended light absorption ability, enhanced charge separation, and larger active sites. This study is the first example of photocatalytic hydrogen evolution from water by using Ni- and Co-doped binary BP/WS2 heterojunctions. [ABSTRACT FROM AUTHOR]

Construction of synergistic photocatalysis system is regarded as an important concept for effectively utilizing solar energy. Herein, Ag nanoparticles decorated SnO 2 flower-like structure is designed and fabricated to synergistically realize efficient hydrogen production from water splitting. According to the results of density functional theory simulations and corresponding experimental analyses, it is identified that interfacial charge coupling of composite system intrinsically facilitate the efficient interfacial charge migration and separation. Moreover, introducing Ag nanoparticles not only expands response range of incident light for SnO 2 through LSPR effect but also reduces the hydrogen adsorption free energy in the catalytic process. Eventually, contributed by the enhanced interaction between reactants and catalysts and optimized carrier behavior, Ag/SnO 2 exhibits a faster hydrogen production rate than SnO 2. The research method designed in this paper may provide a new idea for research of photocatalyst for photocatalytic hydrogen evolution. [Display omitted] • LSPR effect of Ag expands the incident light response range of SnO 2. • Introduction of Ag improves carrier migration environment and carrier separation efficiency. • Enhanced interaction between reactants and catalysts is achieved. • Ag/SnO 2 exhibits enhanced photocatalytic hydrogen evolution. [ABSTRACT FROM AUTHOR]

Dual cocatalysts play an important role in photocatalytic water splitting to hydrogen production. In this paper, Fe-doped Co 3 O 4 (Fe-Co 3 O 4) and Pt were loaded on the surface of g -C 3 N 4 to enhance the water photocatalytic splitting, in which Fe-Co 3 O 4 was used as an oxidation cocatalyst to capture the photo-generated holes of g -C 3 N 4 , and Pt was used as a reduction cocatalyst to transfer photo-generated electrons. Under the irradiation of visible light, its hydrogen production rate reaches up to 3.015 mmol g−1 h−1, which is 3.01 times higher than that of g -C 3 N 4 loaded with Pt. Pt and Fe-Co 3 O 4 dual cocatalysts not only promote the migration rate of photo-generated electrons and holes on the surface of g -C 3 N 4 , but also improve the light absorption capacity of visible light. The interfacial electric field built from the p-n heterojunction of Fe-Co 3 O 4 / g -C 3 N 4 drives photo-generated electrons in Fe-Co 3 O 4 flowing to the holes of g -C 3 N 4 , which further inhibiting the recombination of g -C 3 N 4 photo-generated carriers. This work provides a reference for the development of high-efficiency photocatalyst and an effective support for the development of semiconductor cocatalyst. Pt and CN form a Schottky junction to promote the migration rate of photogenerated electrons. Fe-Co 3 O 4 and CN form a p-n junction, the local electric field at the interface consumes useless photogenerated carriers. The two synergistically enhance the photocatalytic hydrogen production performance. [Display omitted] [ABSTRACT FROM AUTHOR]

Extending the absorption spectrum of TiO2 to include more visible light is of great importance to boost the photocatalytic efficiency for hydrogen generation and environmental pollution removal. Chemical doping and microstructure optimization are both effective. However, integrating them into one system at a low cost is a big challenge. Herein, we reported that phosphorus(V) and Titanium(III) were codoped into leaf‐architectured TiO2 via a facile sol‐gel biotemplating approach, which leads to significantly enhanced visible light harvesting and solar photocatalysis. P(V) doping at a moderate level (1.76 atm%) stabilized Ti(III) to achieve heavy self‐doping (Ti(III):Ti(IV) = 1:44) and concurrent oxygen vacancies of high concentration. The bandgap was narrowed to be only 1.9~2.3 eV. The synergistic co‐doping, coupling with the leaf‐architecture, allows efficient light absorption of less than 539~653 nm, as well as improved charge separation/transfer. The solar photocatalytic degradation rate is 2.6 times higher than that for a commercial TiO2 of P25 towards crystal violet. This work would push forward leaf‐architectured TiO2 toward practical application in photocatalysis, given the abundance, low cost, and renewability of green leaves. The codoping strategy combining sol‐gel and biotemplating approaches is potential for the synthesis of photo‐response materials or systems beyond photocatalysis. [ABSTRACT FROM AUTHOR]