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101.
《International Journal of Hydrogen Energy》2022,47(16):9566-9578
The construction of heterostructure is an effective strategy to synergetically couple wide-band-gap with the narrow-band-gap semiconductor with a mediate optical property and charge transfer capability. Herein, the Z-Scheme CdS/ZnSnO3 (CdS/ZSO) heterostructures were constructed by anchoring CdS nanoparticles on the surface of double-shell hollow cubic ZnSnO3 via the hydrothermal method. The direct recombination of excited electrons in the conduction band (CB) of ZSO and holes in the valence band (VB) of CdS via d-p conjugation at the interface greatly accelerated the internal electric field (IEF). The transfer mode follows the Z-Scheme mechanism, where CdS/ZSO synergistically facilitates the efficient charges transfer from CdS to ZnSnO3 through the intimate interface. Here, ZnSnO3 and CdS serve as an oxidation photocatalyst (OP) and reduction photocatalyst (RP), respectively. Thus, it can promote synergistically the oxidation half-reaction and reduction half-reaction of H2 evolution. The density-functional theory (DFT) calculation further confirms the charges transfer from CdS to ZnSnO3. The hydrogen evolution of 5% CdS/ZSO heterostructure reached 1167.3 μmol g?1, which was about 8 and 3 folds high compared to pristine ZSO (141.9 μmol g?1) and CdS (315.5 μmol g?1), during 3 h of reaction respectively. Furthermore, the CdS/ZSO heterostructures could suppress the photo corrosion of CdS, resulting in its high stability. This work is expected to enlighten the rational design of heterostructure for OP and RP to promote the hybrid heterostructures photocatalytic H2 evolution. 相似文献
102.
《International Journal of Hydrogen Energy》2022,47(52):22045-22053
As a novel co-catalyst, Ti3C2 MXene has an excellent prospect in the field of photocatalysis. Herein, the 2D/3D Ti3C2 MXene@CdS nanoflower (Ti3C2@CdS) composite was successfully synthesized by a hydrothermal method. The combination of 2D Ti3C2 MXene and 3D CdS nanoflowers can promote carrier transfer and separation, which can improve the performance of CdS. Compared to pure CdS nanoflowers, Ti3C2@CdS composite presents lower photoluminescence intensity, longer fluorescence lifetime, higher photocurrent density and smaller electrochemical impedance. The Ti3C2@CdS composite with 15 wt% Ti3C2 adding amount presents high photocatalytic hydrogen evolution activity (88.162 μmol g?1 h?1), 91.57 times of pure CdS. The improved photocatalytic activity of Ti3C2@CdS composite is ascribed to the addition of lamellar Ti3C2 MXene, which improves the electrical conductivity of the photocatalytic system and effectively accelerates the excited electrons transfer from CdS to Ti3C2 MXene. 相似文献
103.
《International Journal of Hydrogen Energy》2022,47(76):32531-32542
Constructing active sites on photocatalysts is one of the most effective approaches for promoting photocatalytic H2 production activity. In this paper, a p-type semiconductor α-NiS is in-situ grown on an n-type semiconductor CdS by a simple solid state method, which results in a strong interfacial contact between α-NiS and CdS. Benefitting from the built-in electric field caused by a p-n junction, the photoinduced electrons of CdS and holes of α-NiS migrate to their interface and recombine rapidly, which results in the formation of a Z system. The more negative CB potential of α-NiS/CdS possesses stronger ability to reduce H+ to H2, thereby exhibiting higher photocatalytic H2 evolution activity. Furthermore, the strong interface contact is beneficial to the charge migration and promotes the charge separation efficiency. The H2 evolution rate of 1.0% α-NiS/CdS reaches 9.8 mmol h?1 g?1, corresponding to an AQY of 65.7% at λ = 420 nm. 相似文献
104.
《International Journal of Hydrogen Energy》2023,48(6):2200-2210
The development of excellent photocatalysts for hydrogen evolution is of great significance to solving the global energy crisis. In this work, a novel 3D hierarchical CdS/NiAl-LDH photocatalyst was fabricated by a facile electrostatic assembly strategy, which was composed of 1D CdS nanorods and 3D flower-like NiAl-LDH microspheres. Under the visible irradiation, the CNA-20 hierarchical photocatalyst presents the optimum hydrogen evolution rate achieved to 3.24 mmol g?1 h?1, which is improved 6.23-fold in comparison with the pure CdS. Through the analysis of energy band structures and first-principles calculation, the type-Ⅱ charge transfer mechanism was proposed. Driven by the built-in electric field, as well as the effect of intimate interface contact of CdS and NiAl-LDH, the photogenerated charge could be achieved rapidly separate and migrate, which effectively promotes the H2 evolution. This well-designed synergistic 1D/3D interface interaction and provides an economic approach to rationally developing metal-free photocatalysts for hydrogen production. 相似文献
105.
《International Journal of Hydrogen Energy》2023,48(42):15908-15920
Constructing an efficient photoelectron transfer route to improve carrier separation efficiency is crucial for photocatalytic hydrogen evolution. In this work, CdS/Cu2S/SiO2 heterostructure with one-dimensional hollow tube morphology was designed by the solvothermal method using CuO/SiO2 hollow tube as carrier. The hexagonal phase CdS and sulfur vacancies were adjusted simultaneously by the reduction strategy of NaBH4 aqueous solution. CdS/CuS/SiO2 with cubic phase CdS was synthesized in the absence of NaBH4 aqueous solution. CdS/Cu2S/SiO2 was characterized by SEM, TEM, XRD, XPS, SPV and so on. The results showed that hexagonal CdS and sulfur vacancies benefited the separation of photo-generated carriers. As a consequence, the CdS/Cu2S/SiO2-10 composite exhibited a high photocatalytic hydrogen production rate (1196.98 μmol/g/h), and its performance almost 7.18 times than that of CdS/CuS/SiO2. Moreover, CdS/Cu2S/SiO2-10 showed an excellent cyclic stability. This was attributed to the strong electron interaction of CdS/Cu2S/SiO2 heterostructure and the sulfur vacancy acted as an electron trap, enhancing the separation of photo-induced electrons and holes. 相似文献
106.
A series of CdS/M(x)-MCM-41 (M = Zr, Ti, x stands for molar ratio of M/Si) photocatalysts were preprared by hydrotherm, ion-exchange and sulfidation process. The catalysts were characterized by X-ray diffraction, UV-vis spectra and N2 adsorption-desorption isotherm et al. The characterization results shown that Zr or Ti was successfully doped into the mesoporous of MCM-41, and CdS was also successfully incorporated into such modified mesoporous. The results of photocatalytic performance for hydrogen production shown that CdS/Zr(0.005)-MCM-41 and CdS/Ti(0.02)-MCM-41 had the highest hydrogen evolution activity in triethanolamine aqueous solution under visible light (λ > 430 nm) irradiation, which can be explained by the diffusion velocity of the reactants and resultants and the protection which MCM-41 provided for CdS. 相似文献
107.
《International Journal of Hydrogen Energy》2017,42(27):17394-17402
In this paper, ZnS/CdS core/shell nanotubes were successfully synthesized by combining hydrothermal treatment and ion exchange conversion, and the significant influence of CdS content in the shell on photo absorption and photocatalytic activity was also investigated. The core/shell nanotubes structure of CdS deposition on both sides of ZnS nanotube was confirmed by scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The room temperature PL spectra of ZnS/CdS core/shell nanotubes indicated that CdS on the shell can reduce the recombination of photon-generated electron and hole. The photocatalytic activity tests prove that ZnS/CdS nanotubes have much higher photocatalytic hydrogen production activity than ZnS nanotube and CdS nanotube. Under the irradiation of visible light, the highest photocatalytic hydrogen production rate of 110 μmol h−1 g−1 is observed over the ZnS/CdS core/shell nanotubes with CdS/ZnS molar ratio of 1:4, which is about 11.02 and 5.56 times more active than ZnS nanotube and CdS nanotube, respectively. The improved performance of ZnS/CdS samples can be due to the strong photo response in the visible light region and the efficient separation of electron–hole pairs. 相似文献
108.
《International Journal of Hydrogen Energy》2020,45(53):28437-28446
Exploiting efficient and stable noble metal-free hydrogen evolution catalysts for water splitting is of great importance. In this work, NixCo1-xO@C/CdS hybrid is successfully fabricated through an electrostatic interaction of oppositely charged nanoparticles on their surfaces. The resulting NixCo1-xO@C nanoboxes cocatalysts which were derived from NiCo-LDH@ZIF-67 with Ni–Co layered double hydroxides (LDH) decorated with ZIF-67 precursor exhibited improved hydrogen production rate compared with bare CdS semiconductor from 0.7 mmol g−1 h−1 to 56 mmol g−1 h−1. It is demonstrated that the electrostatic interaction between the two surface charged nanoparticles of NixCo1-xO@C and CdS play an important role in migrating and separating of photogenerated charge carriers. The synthesized NixCo1-xO@C as excellent candidates for cost-effective cocatalysts is aimed to substitute for noble metals in photocatalytic H2 evolution. 相似文献
109.
《International Journal of Hydrogen Energy》2020,45(56):31678-31688
Solar photocatalytic water splitting using particulate semiconductors has been valued as a potentially scalable way for the production of clean H2 energy, yet the performances of the powder-suspension systems are constrained by insufficient utilization of light energy and tedious recycling of photocatalyst particles. Here, we present a high-performance photocatalytic H2 evolution using a visible-light-driven CdS-based monolithic photocatalyst with three-dimensional (3D) heterostructure. The monolithic photocatalyst is fabricated by firmly growing CdS microspheres on a Ni(OH)2 nanosheet-modified Ni foam (NF) (denoted as CdS-NiSx/NF) via a simple hydrothermal process. The structure and component synergy endows the monolithic CdS-NiSx/NF photocatalyst advantageous features including high-density CdS microspheres for visible light harvesting, multiple heterojunction interfaces for efficient electron-hole separation, and abundant interfacial NiSx active sites for efficient H2 evolution reaction (HER). Upon visible light irradiation, the monolithic CdS-NiSx/NF photocatalyst exhibits an outstanding photocatalytic H2 evolution activity with an enhanced rate of 6.2 mmol·h−1 g−1CdS, which is 6 times higher than that of the suspended CdS powder. In addition, the structural integrity of the CdS-NiSx/NF enables a good stability for H2 evolution over a 30 h reaction. This monolithic photocatalyst is scalable in preparation and compatible for device fabrication, which offers great potentials for applications in solar cells, photoelectrocatalysis, and electrocatalysis. 相似文献
110.
《International Journal of Hydrogen Energy》2020,45(11):6476-6486
Synergistic the modulation of photon absorption capability and interfacial charge transfer of the photocatalyst are highly required for developing high-performance heterojunction photocatalysts. The ternary CdS-graphene quantum dots-titanate nanotubes (CdS-GQDs-TNTs) nanocomposite have been prepared by an in situ growth method. The physicochemical characterization reveals that the GQDs are firmly decorated on both inner and outer surface of TNT through the formation of Ti–O–C chemical bonding, and CdS QDs are loaded on the outer surface of TNTs through strong interfacial interaction. The intimate integrated CdS-GQDs-TNTs nanocomposite exhibits much superior photocatalytic performance toward H2 production compared with binary GQDs-TNTs and pure TNTs photocatalyst, which can be attributed to the combined interaction of the stronger visible light harvesting, the longer lifetime of photogenerated electron−hole pairs, faster interfacial charge transfer rate, fast and long-distance electron transport pass. The interfacial charge transfer mechanism of CdS-GQDs-TNTs ternary composite are proposed based on photoelectrochemical measurements. 相似文献