Constructing BiVO4-Au@CdS photocatalyst with energic charge-carrier-separation capacity derived from facet induction and Z-scheme bridge for degradation of organic pollutants
“…As a promising O 2 evolution reaction (OER) catalyst, BiVO 4 has become hot research topic owing to its environmental friendliness, good stability, and narrow bandgap alignment. [ 11,14 ] However, it is not a good candidate for overall water splitting because its conduction band (CB) is lower than the H 2 O reduction potential, and its OER activity is still unsatisfactory due to the slow charge separation, finite visible light absorption and insufficient charge‐induced reaction efficiency. [ 14–17 ] In the wake of developments of 2D materials, BiVO 4 nanosheets are highly desired for their high specific surface area, plentiful active sites, and outstanding electronic conductivity, which can effectively abate the charge diffusion distance and charge recombination.…”
This work shows a novel artificial Z‐scheme photosystem based on a heterometallic Zn‐/Pt‐porphyrin conjugated polymer (ZnPtP‐CP) grafted onto ultrathin BiVO4 nanosheets via Zn–O–V bridging bonds for high‐efficiency overall water photosplitting. An impressive apparent quantum yield of 9.85% at λ = 400 nm is achieved over the resulting ZnPtP–CP/BiVO4 composite, in which BiVO4 nanosheets are in close contact with ZnPtP‐CP nanosheets via Zn–O–V bridging bonds to promote a Z‐scheme charge transfer mechanism with ZnPtP‐CP serving as electron‐rich unit and BiVO4 as hole‐rich one. The photoexcited electrons of BiVO4 transfer to the interface and recombine with the photogenerated holes of ZnPtP‐CP through the Zn–O–V bonds, and thus the strong reducibility of the photoinduced electrons in ZnPtP‐CP and the strong oxidation ability of the photogenerated holes in BiVO4 are maintained. Moreover, the highly dispersed Pt centers (PtN4) in Pt‐porphyrin bridging units act as single‐atom catalytic sites to facilitate a cascade charge transfer by fast migration of the photogenerated electrons from Zn‐porphyrin to Pt‐porphyrin units for the water reduction reaction. This Z‐scheme mechanism with two‐step excitation and cascade charge transfer pathway makes the composite acting as Z‐scheme dual‐function photocatalyst responsible for the efficient solar‐driven overall water photosplitting without the aid of a sacrificial reagent or external bias.
“…As a promising O 2 evolution reaction (OER) catalyst, BiVO 4 has become hot research topic owing to its environmental friendliness, good stability, and narrow bandgap alignment. [ 11,14 ] However, it is not a good candidate for overall water splitting because its conduction band (CB) is lower than the H 2 O reduction potential, and its OER activity is still unsatisfactory due to the slow charge separation, finite visible light absorption and insufficient charge‐induced reaction efficiency. [ 14–17 ] In the wake of developments of 2D materials, BiVO 4 nanosheets are highly desired for their high specific surface area, plentiful active sites, and outstanding electronic conductivity, which can effectively abate the charge diffusion distance and charge recombination.…”
This work shows a novel artificial Z‐scheme photosystem based on a heterometallic Zn‐/Pt‐porphyrin conjugated polymer (ZnPtP‐CP) grafted onto ultrathin BiVO4 nanosheets via Zn–O–V bridging bonds for high‐efficiency overall water photosplitting. An impressive apparent quantum yield of 9.85% at λ = 400 nm is achieved over the resulting ZnPtP–CP/BiVO4 composite, in which BiVO4 nanosheets are in close contact with ZnPtP‐CP nanosheets via Zn–O–V bridging bonds to promote a Z‐scheme charge transfer mechanism with ZnPtP‐CP serving as electron‐rich unit and BiVO4 as hole‐rich one. The photoexcited electrons of BiVO4 transfer to the interface and recombine with the photogenerated holes of ZnPtP‐CP through the Zn–O–V bonds, and thus the strong reducibility of the photoinduced electrons in ZnPtP‐CP and the strong oxidation ability of the photogenerated holes in BiVO4 are maintained. Moreover, the highly dispersed Pt centers (PtN4) in Pt‐porphyrin bridging units act as single‐atom catalytic sites to facilitate a cascade charge transfer by fast migration of the photogenerated electrons from Zn‐porphyrin to Pt‐porphyrin units for the water reduction reaction. This Z‐scheme mechanism with two‐step excitation and cascade charge transfer pathway makes the composite acting as Z‐scheme dual‐function photocatalyst responsible for the efficient solar‐driven overall water photosplitting without the aid of a sacrificial reagent or external bias.
“…It is obvious that the K3Ti5NbO14 shows the weakest visible light response due to the original wide band gap of pure K3Ti5NbO14. After combining with TiO2, the photocurrent intensity of TNT is nearly 2 times than that of the K3Ti5NbO14, which may be due to the promoted separation of photogenerated charge carriers and accelerated transfer of the interfacial charge derived from the formed heterojunction structure [40,41]. After further doping by N, the sample of NTNT shows the higher photocurrent intensity than TNT.…”
A novel N-doped K3Ti5NbO14@TiO2 (NTNT) core-shell heterojunction photocatalyst was synthesized by firstly mixing titanium isopropoxide and K3Ti5NbO14 nanobelt, and then calcinating at 500 °C in air using urea as the nitrogen source. The samples were analyzed by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopic (XPS) spectra. Anatase TiO2 nanoparticles were closely deposited on the surface of K3Ti5NbO14 nanobelt to form a nanoscale heterojunction structure favorable for the separation of photogenerated charge carriers. Meanwhile, the nitrogen atoms were mainly doped in the crystal lattices of TiO2, resulting in the increased light harvesting ability to visible light region. The photocatalytic performance was evaluated by the degradation of methylene blue (MB) under visible light irradiation. The enhanced photocatalytic activity of NTNT was ascribed to the combined effects of morphology engineering, N doping and the formation of heterojunction. A possible photocatalytic mechanism was proposed based on the experimental results.
“…The surface chemistry of the as-prepared composite has the greatest impact on its photocatalytic activity. X-ray photoelectron spectroscopy (XPS) characterization has been extensively used to determine the surface chemistry of materials [57] by studying the changes in the electronic density on the different surfaces of a photocatalyst through investigating the shift in the binding energies [58]. A shift in the binding energy of a specific element of the semiconductor is caused by the introduction of the foreign materials which affects the electron migration on its surface [25, 31]…”
Section: Characterization Methods For Heterostructure G-c3n4mentioning
confidence: 99%
“…In their report, photocatalytic activity of ZIF-NC/g-C 3 N 4 for the degradation of bisphenol A (BPA) in aqueous solution reached the removal rate of 97% after 60 min of irradiation with 0.5% ZIF-NC content. Excessive addition of the ZIN-NC to 1% over g-C 3 N 4 surfaces hinder the light adsorption of g-C 3 N 4 which results in low generation of electron–hole pairs on g-C 3 N 4 , hence resulting to decreased photocatalytic activity [58]. Fig.…”
Section: Photocatalytic Applications Of Heterostructure G-c3n4mentioning
Fabrication of the heterojunction composites photocatalyst has attained much attention for solar energy conversion due to their high optimization of reduction-oxidation potential as a result of effective separation of photogenerated electrons-holes pairs. In this review, the background of photocatalysis, mechanism of photocatalysis, and the several researches on the heterostructure graphitic carbon nitride (g-C
3
N
4
) semiconductor are discussed. The advantages of the heterostructure g-C
3
N
4
over their precursors are also discussed. The conclusion and future perspectives on this emerging research direction are given. This paper gives a useful knowledge on the heterostructure g-C
3
N
4
and their photocatalytic mechanisms and applications.
Impact Statements
The paper on g-C3N4 Nano-based photocatalysts is expected to enlighten scientists on precise management and evaluating the environment, which may merit prospect research into developing suitable mechanism for energy, wastewater treatment and environmental purification.
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