In this work, plasmonic Au/SnO2/g‐C3N4 (Au/SO/CN) nanocomposites have been successfully synthesized and applied in the H2 evolution as photocatalysts, which exhibit superior photocatalytic activities and favorable stability without any cocatalyst under visible‐light irradiation. The amount‐optimized 2Au/6SO/CN nanocomposite capable of producing approximately 770 μmol g−1 h−1 H2 gas under λ > 400 nm light illumination far surpasses the H2 gas output of SO/CN (130 μmol g−1), Au/CN (112 μmol g−1 h−1), and CN (11 μmol g−1 h−1) as a contrast. In addition, the photocatalytic activity of 2Au/6SO/CN maintains unchanged for 5 runs in 5 h. The enhanced photoactivity for H2 evolution is attributed to the prominently promoted photogenerated charge separation via the excited electron transfer from plasmonic Au (≈520 nm) and CN (470 nm > λ > 400 nm) to SO, as indicated by the surface photovoltage spectra, photoelectrochemical I–V curves, electrochemical impedance spectra, examination of formed hydroxyl radicals, and photocurrent action spectra. Moreover, the Kelvin probe test indicates that the newly aligned conduction band of SO in the fabricated 2Au/6SO/CN is indispensable to assist developing a proper energy platform for the photocatalytic H2 evolution. This work distinctly provides a feasible strategy to synthesize highly efficient plasmonic‐assisted CN‐based photocatalysts utilized for solar fuel production.
Covalent-organic frameworks (COFs) have been recognized as a new type of promising photocatalysts for hydrogen evolution. To investigate how different functional groups attached in the backbone of COFs affect the overall photocatalytic H 2 evolution, for the first time, we selected and synthesized a series of ketoenamine-based COFs with the same host framework as model system. It includes TpPaÀ COFÀ X (X =À H, À (CH 3 ) 2 , and À NO 2 ) with three different groups attached in the backbone of TpPaÀ COF. We systematically investigated the differences in morphology, light-absorption intensity and band gap of these 2D COFs. The results of photocatalytic H 2 evolution measurements indicate that the TpPaÀ COFÀ (CH 3 ) 2 shows the best activity, while the activity of TpPaÀ COFÀ NO 2 is relatively low compared to that of other two COFs in the system. Moreover, the separation ability of photogenerated charge was also followed the order of TpPaÀ COFÀ (CH 3 ) 2 > TpPaÀ COF > TpPaÀ COFÀ NO 2 . The best photocatalytic H 2 production performance of TpPaÀ COFÀ (CH 3 ) 2 in these systems should be mainly attributed to the better electron-donating ability of À CH 3 groups compared to À H or À NO 2 group, which result in more efficient charge transferring in the inner of the material. This work demonstrates that reasonably adding electrondonating group in TpPaÀ COFs can lead to a better photocatalytic H 2 evolution activity, and which is meaningful for further design of efficient COF-based photocatalysts for H 2 evolution.[a] J.
The configuration regulation of single‐atom photocatalysts (SAPCs) can significantly influence the interfacial charge transfer and subsequent catalytic process. The construction of conventional SAPCs for aqueous CO2 reduction is mainly devoted toward favorable activation and photoreduction of CO2, however, the role of water is frequently neglected. In this work, single Ni atoms are successfully anchored by boron‐oxo species on g‐C3N4 nanosheets through a facile ion‐exchange method. The dative interaction between the B atom and the sp2 N atom of g‐C3N4 guarantees the high dispersion of boron‐oxo species, where O atoms coordinate with single Ni (II) sites to obtain a unique six‐oxygen‐coordinated configuration. The optimized single‐atom Ni photocatalyst, rivaling Pt‐modified g‐C3N4 nanosheets, provides excellent CO2 reduction rate with CO and CH4 as products. Quasi‐in‐situ X‐ray photoelectron spectra, transient absorption spectra, isotopic labeling, and in situ Fourier transform infrared spectra reveal that as‐fabricated six‐oxygen‐coordinated single Ni (II) sites can effectively capture the photoelectrons of CN along the BO bridges and preferentially activate adsorbed water to produce H atoms to eventually induce a hydrogen‐assisted CO2 reduction. This work diversifies the synthetic strategies for single‐atom catalysts and provides insight on correlation between the single‐atom configuration and reaction pathway.
Die rationale Entwicklung effizienter Photokatalysatoren mit günstiger Ladungstrennung und breiter spektraler Absorption ist entscheidend für eine ökonomische Umwandlung von Solarenergie in chemische Energie. F. Q. Bai, J. Tang, L. Q. Jing et al. zeigen in ihrer Zuschrift auf S. 10989 H‐verbrückte ZnPc/BiVO4‐Nanokomposite als ultradünnen, räumlich angepassten 2D/2D‐Heteroübergang zur effizienten photokatalytischen CO2‐Reduktion über eine breite Region des sichtbaren Lichts.
Realization of solar‐driven aerobic organic transformation under atmospheric pressure raises the great challenge for efficiently activating O
2
by tailored photocatalysts. Guided by theoretical calculation, phosphate groups are used to induce the construction of ultrathin Co phthalocyanine/g‐C
3
N
4
heterojunctions (CoPc/P‐CN, ≈4 nm) via strengthened H‐bonding interfacial connection, achieving an unprecedented 14‐time photoactivity improvement for UV–vis aerobic 2,4‐dichlorophenol degradation compared to bulk CN by promoted activation of O
2
. It is validated that more
•
O
2
−
radicals are produced through the improved photoreduction of O
2
by accelerated photoelectron transfer from CN to the ligand of CoPc and then to the abundant single Co–N
4
(II) catalytic sites, as endowed by the matched dimension, intimate interface even at the molecular level, and high CoPc dispersion of resulted heterojunctions. Interestingly, CoPc/P‐CN also exhibits outstanding photoactivities in the aerobic oxidation of aromatic alcohols. This work showcases a feasible route to realize efficient photocatalytic O
2
activation by exploiting the potential of ultrathin metal phthalocyanine (MPc) assemblies with abundant single‐atom sites. More importantly, a universal facile strategy of H‐bonding‐dominating construction of MPc‐involved heterojunctions is successfully established.
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