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1.
《International Journal of Hydrogen Energy》2022,47(1):228-241
The construction of semiconductor heterojunction for photocatalytic H2 production from water splitting is an efficient and environment-friendly technology. In this work, ZnO/BiOCl (ZBC) and Sn-doped ZnO/BiOCl (ZBC-S) photocatalysts with Z-scheme heterojunction were successfully prepared by simple hydrothermal method. The photocatalytic H2 evolution from water splitting by the as-prepared photocatalysts was investigated. The formation of ZnO/BiOCl heterojunction reduces the recombination probability of the photogenerated carriers. The impurity levels originated from Sn doping reduce the band gap width of ZnO and BiOCl to some extent, thereby enhancing the light absorption ability. The ZBC-S composite exhibits the best photocatalytic activity. In addition, the photocatalytic efficiency of H2 production was improved by sensitization with Eosin Y (EY) dye. The H2 production rate under simulated sunlight reaches 4146.77 μmol g?1 h?1, which is 27 times higher than that of pure ZnO. Finally, the Z-scheme electron transfer route in ZnO/BiOCl heterojunction was determined, and the photocatalytic H2 production mechanism of EY sensitized ZBC-S was proposed. 相似文献
2.
《International Journal of Hydrogen Energy》2020,45(53):28394-28403
Solar energy utilization is a promising strategy for the photocatalytic generation of H2 from water. Herein, a CuS-modified ZnO rod/reduced graphene oxide (rGO)/CdS heterostructure was fabricated via Cu-induced electrochemical growth with Zn powder at room temperature. The resulting powder revealed good interfacial bonding and promoted photoexcited carrier transport. The CuS nanoparticles played a pivotal role in enhancing visible-light responses and demonstrated excellent catalytic performance. A high visible-light photocatalytic H2 generation rate of 1073 μmol h−1 g−1 was obtained from the CuS–ZnO/rGO/CdS heterostructure containing 0.23% CuS and 1.62% CdS. Increased photoexcited electron lifetimes, improved carrier transport rates, and decreased fluorescence intensities confirmed the synergistic effects of each of the components of the heterostructure. This study provides an innovative strategy for constructing multi-component heterostructures to achieve efficient visible-light H2 evolution. 相似文献
3.
4.
《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
5.
《International Journal of Hydrogen Energy》2020,45(11):6291-6301
The MoS2/Ti3C2 catalyst with a unique sphere/sheet structure were prepared by hydrothermal method. The MoS2/Ti3C2 heterostructure loading 30% Ti3C2 has a maximum hydrogen production rate of 6144.7 μmol g−1 h−1, which are 2.3 times higher than those of the pure MoS2. The heterostructure maintains a high catalytic activity within 4 cycles. The heterostructure not only effectively reduce the recombination of photogenerated electrons and holes, but also provide more activation sites, which promotes the photocatalytic hydrogen evolution reaction (HER). These works can provide reference for the development of efficient catalysts in photocatalytic hydrogen evolution. 相似文献
6.
《International Journal of Hydrogen Energy》2022,47(14):8829-8840
Lead-free Cs2AgBiBr6 (CABB) double perovskite as a new-type photocatalytic material alternative to lead halide perovskites holds promise to implement the solar-H2 conversion, but the interior recombination of photo-generated carriers and thus low photocatalytic hydrogen evolution reaction (HER) rate of CABB restrict its further industrial applications. Herein, we report the composite fabrication of MoS2/CABB heterostructure for high-efficiency and durable photocatalytic HER by anchoring non-noble MoS2 onto CABB via a facile dissolution-recrystallization method. The optimized MoS2/CABB performs a visible-light HER rate of 87.5 μmol h?1 g?1 in aqueous HBr solution, ca. 20-fold compared to that of pure CABB (4.3 μmol h?1 g?1), and presents a discontinuous 500-h photocatalytic HER stability with no evident loss. The superb performance of MoS2/CABB can be ascribed to the kinetics-facilitated heterostructure consisting of stable CABB and MoS2. This work proposes a facile and versatile tactic to construct a low-cost Cs2AgBiBr6-based heterostructure for efficient and long-term photocatalytic HER. 相似文献
7.
Longfei Zhao Yuan Zhang Zhupeng Ye Xin Chen Yanwei Zeng 《International Journal of Hydrogen Energy》2021,46(13):9040-9051
Constructing heterostructure is regarded as one of the most promising strategies for the enhancement of photocatalytic activities, because it can make charge carriers separated more efficiently at the interface. Herein, CdS-WO3 heterostructure photocatalysts with highly ordered and intimate interfacial structure between the two constituent phases have been successfully prepared via a heterogeneous nucleation and growth of CdS nanoparticles on the surface of WO3 nanorods, which were fulfilled through a controlled release of S2? in the aqueous solution containing Cd2+ by the reaction of NH3 with thioacetamide. The as-prepared photocatalysts were carefully studied in morphology and interfacial structure by FESEM and HRTEM, along with the other characterizations by XRD, XPS, and UV–visible absorption spectra. Under the irradiation of mercury lamp, the photocatalyst with 6 wt% CdS could afford a degradation rate of methyl orange (MO) of 94.6% in 70 min, 5.84 and 2.51 times as high as WO3 and CdS, through a photocatalytic degradation process mainly controlled by·O2? as active species. In view of the distinctive alignment of energy bands of CdS-WO3, the enhanced photocatalytic activities should be attributed to the more efficient Z-scheme mechanism that allows the photogenerated holes in WO3 and electrons in CdS to function more efficiently thanks to the efficient interfacial recombination of the electrons in WO3 and holes in CdS. 相似文献
8.
《International Journal of Hydrogen Energy》2022,47(13):8294-8302
Photocatalytic water splitting to produce hydrogen has attracted extensive attention and exhibited broad development prospects. In this work, CuInS2 microflowers were fabricated through the solvothermal method, and decorated with CdSe quantum dots on the surface. As-prepared CdSe/CuInS2 microflowers exhibited high photocatalytic hydrogen production activity (10610.37 μmol g?1 h?1) and high AQE of 48.97% at 420 nm. The enhanced photocatalytic hydrogen production activity owing to the construction of p-n heterostructure improved light absorption ability, increased electrons transfer efficiency and reduced recombination of photo-induced electrons and holes. Moreover, high stability and cyclic utilization of CdSe/CuInS2 microflowers were beneficial to photocatalytic hydrogen production application. 相似文献
9.
Yi Zhao Yarui Guo Jibiao Li Ping Li 《International Journal of Hydrogen Energy》2021,46(36):18922-18935
Developing efficient, stable, and cheap photocatalysts for H2 production has aroused great interest among researchers. Herein, noble-metal-free ZnO/SrTiO3 composite photocatalysts have been successfully prepared by hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffusion spectroscopy, and photoluminescence spectroscopy are used to characterize the obtained samples. The photocatalytic water splitting for H2 production by ZnO/SrTiO3 has been studied under simulated sunlight irradiation by using triethanolamine as a sacrificial agent and Eosin Y (EY) dye as a sensitizer. The orthogonal experiments are designed to optimize the photocatalytic reaction conditions for practical purposes. The influencing extents and trends of the factors have been investigated, including the catalyst composition and dosage, pH value of the solution, triethanolamine, and EY addition. Under the optimum conditions, the H2 production rate with ZnO/SrTiO3 is up to 16006.12 μmol g?1 h?1. The excellent performance of ZnO/SrTiO3 is attributed to the formation of a step-scheme (S-scheme) heterojunction, which promotes the separation of photocarriers and reduces their recombination probability. 相似文献
10.
《International Journal of Hydrogen Energy》2022,47(65):27961-27972
Designing an efficient heterojunction interface is an effective way to promote the electrons' transfer and improve the photocatalytic H2 evolution performance. In this work, a novel hollow hybrid system of Co@NC/CdS has been fabricated and constructed. CdS nanospheres are anchored on the hollow-structured cobalt incorporated nitrogen-doped carbon (Co@NC) through a one-pot in-situ chemical deposition approach, forming an intimate interface and establishing an excellent channel to improve the electrons transfer and charge carriers separation between CdS and Co@NC cocatalyst, which immensely promotes the photocatalytic activity. The rate of photocatalytic H2 evolution over hollow structured Co@NC/CdS heterojunction can be achieved 8.2 mmol g?1 h?1, which is about 45 times of pristine CdS nanospheres. The photocatalytic H2 evolution mechanism has been investigated by the techniques of photoluminescence (PL) spectra, photocurrent-time (i-t) curves, electrochemical impedance spectroscopy (EIS) etc. This work aims to provide a new way in developing of high-performance advanced 3D heterojunction for photocatalytic hydrogen evolution. 相似文献
11.
《International Journal of Hydrogen Energy》2022,47(81):34397-34409
Constructing 2D/2D heterojunction photocatalysts has attracted great attentions due to their inherent advantages such as larger interfacial contact areas, short transfer distance of charges and abundant reaction active sites. Herein, 2D/2D CoP/CdS heterojunctions were successfully fabricated and employed in photocatalytic H2 evolution using lactic acid as sacrificial reagents. The multiple characteristic techniques were adopted to investigate the crystalline phases, morphologies, optical properties and textual structures of heterojunctions. It was found that integrating 2D CoP nanosheets as cocatalysts with 2D CdS nanosheets by Co–S chemical bonds would significantly boost the photocatalytic H2 evolution performances, and the 7 wt% 2D/2D CoP/CdS heterojunction possessed the maximal H2 evolution rate of 92.54 mmol g?1 h?1, approximately 31 times higher than that of bare 2D CdS nanosheets. Photoelectrochemical, steady photoluminescence (PL) and time-resolved photoluminescence (TRPL) measurements indicated that there existed an effective charge separation and migration over 2D/2D CoP/CdS heterojunction, which then markedly lengthened the photoinduced electrons average lifetimes, retarded the recombination of charge carriers, and caused the dramatically boosted photocatalytic H2 evolution activity. Moreover, the density functional theory (DFT) calculation further corroborated that the efficient charge transfer occurred at the interfaces of CoP/CdS heterojunction. This present research puts forward a promising strategy to engineer the 2D/2D heterojunction photocatalysts endowed with an appealing photocatalytic H2 evolution performance. 相似文献
12.
《International Journal of Hydrogen Energy》2022,47(84):35723-35736
To achieve low-cost photocatalytic hydrogen (H2) production, it is necessary to develop low-priced transition metal co-catalysts to replace the roles of noble metals for photocatalytic H2 evolution. Herein, a co-catalyst of Mo-doped CoSx (Mo-CoSx) was synthesized by using the hydrothermal procedure, then attached to g-C3N4 to construct a composite photocatalyst. As a co-catalyst, Mo-CoSx can work as an electron acceptor, it is utilized to receive electrons generated by g-C3N4 photocatalyst on the surface of the catalyst, and inhibit the recombination of those electrons, thus showing enhanced charge transfer ability as well as reduction ability. The optimized Mo-CoSx/g-C3N4 delivered a prominent photocatalytic H2 evolution rate of 2062.4 μmol h?1 g?1, which was ~193 times higher than g-C3N4. Its AQE at 400 nm and 420 nm were 11.05% and 6.83%, respectively. This work provides a novel non-precious metal co-catalyst/g-C3N4 photocatalyst that is expected to be an acceptable cost route to solar energy conversion. 相似文献
13.
《International Journal of Hydrogen Energy》2022,47(17):9895-9904
Exploiting efficient catalysts is of interest for solar-driven water splitting. Herein, a novel NiWO4/CdS nanosheets-on-nanorods direct Z-Scheme heterostructure was developed by using a facile in-situ approach. The optimized NiWO4/CdS heterostructure shows a H2 evolution rate of 26.43 mmol g?1 h?1 exceeding that of bare CdS by more than 75 folds. Systematic investigations reveal the nanostructures with numerous active sites, intimate contact interface, and enhanced charge separation rate synergistically account for the outstanding performance of the NiWO4/CdS. Moreover, the band structures were detailedly analyzed and the tentative photocatalytic mechanism was proposed, which could contribute to deeply understanding the catalytic process and guide the synthesis of the efficient heterostructure. These findings and strategies may have great significance in promoting the development of highly efficient and low-cost photocatalysts. 相似文献
14.
《International Journal of Hydrogen Energy》2023,48(34):12683-12698
An integration of S-scheme heterojunction catalyst with surface plasmon resonance effect is the prime focus of current research activites in the field of visible light driven photocatalytic hydrogen (H2) evolution. Herein, a sol-gel route is used to design a heterojunction of ZnO–CuO–Au. The effect of process parameters, including irradiation time, catalyst dose, and sacrificial reagents on the hydrogen evolution is studied. The S-scheme ZnO–CuO–Au heterojunction catalyst demonstrated high surface area, better optical absorption response in the visible part of light spectrum, and improved separation and transportion of charge carriers as verified by DRS, PL, and photoelectrochemical studies. The maximum H2 evolution rateof ZnO–CuO–Au reaches 4655 μmolh−1g−1, which is 5 and 3.2 times higher than ZnO–CuO and Au–ZnO catalysts, respectively. A possible reason of this increase in H2 evolution rate is inhibited recombination of charge carriers because of the S-scheme design to increase electrons with strong reduction potential and prolong lifetime, Au serves as an SPR source and conductive channel to swift the transfer of electrons and high density of active sites. This work offers innovative insight into designing plasmonic metals-modified S-scheme systems for solar fuel production. 相似文献
15.
《International Journal of Hydrogen Energy》2023,48(10):3901-3915
Regulating photogenerated charge carrier transfer kinetics in multi-component heterostructure by surface-interface design is of great significance for accelerating efficiently photocatalytic hydrogen evolution reaction. Herein, a novel binary CoSe2/CNNS composite is successfully fabricated by a successive high-temperature calcination method of g-C3N4 followed by in-situ hot injection process of CoSe2 for the first time. The optimal 7.5% CoSe2/CNNS heterostructure reaches moderate hydrogen production rate of 1386.8 μmol·g?1·h?1 and exhibits good mineralization efficiency for tetracycline hydrochloride (40.6%) within 120 min under light irradiation, respectively. The photogenerated charge migration behaviors, the generation process and function of various radical species (H2O2, ·OH and ·O2?) are detailedly analyzed. Moreover, photocatalytic hydrogen evolution reaction process and the intermediates and active species for tetracycline hydrochloride degradation can also be discussed. Such significantly enhanced photocatalytic activity can be resulting from good light trapping ability, rapid photocarriers transfer efficiency and accelerated H2O2 decomposition ability via a continuous two-electron/two-step reduction route. This work provides an effective strategy to control and understand the charge migration kinetics as well as to suppress H2O2 production during photocatalytic hydrogen evolution process. 相似文献
16.
《International Journal of Hydrogen Energy》2022,47(5):2936-2946
A high-efficiency and easy-available approach was developed to obtain a ternary heterojunction composites with advanced hydrogen evolution reaction (HER) performance under visible light by water split. PdAg bimetallic nanoparticles make a close contact interface between g-C3N4(CN) and Zn0.5Cd0.5S(ZCS). Under visible light irradiation, CN and ZCS are both excited to generate electron-hole pairs, PdAg bimetallic nanoparticles act as a bridge between CN and ZCS. Not only can the photogenerated electrons from CN be captured, but they can also be quickly transferred to the surface of ZCS and participate in the photocatalytic reaction to release H2, and the recombination of charge carriers between the contact interface of ZCS and CN can be significantly inhibited. In addition, the thin CN layer reduces the photocorrosion of the ZCS and enhances the specific surface area of the composite material. After testing, the composite material with 30 wt% ZCS and 4 wt% PdAg demonstrates hydrogen evolution performance, up to 6250.7 μmol g?1h?1, which is 753 times the hydrogen evolution rate of single-component CN and 12.6 times of ZCS/CN. Compared with single-component and two-component photocatalysts, the ternary ZCS/PdAg/CN photocatalyst achieves significantly enhanced photocatalytic activity. 相似文献
17.
Xinyuan Xia Lin Tang Hongyan Ji Luyao Kang Zimeng Wei Shanshan Lou Junfeng Xie Bo Tang 《International Journal of Hydrogen Energy》2021,46(45):23311-23321
In this paper, a novel 2D bubble-like g-C3N4 (B–CN) with a highly porous and crosslinked structure is successfully synthesized via a cost-effective bottom-up process. The as-prepared B–CN photocatalyst delivers a considerably expanded specific surface area and increased active sites. Moreover, the 2D bubble-like structure can afford shortened diffusion paths for both photogenerated charge carriers and reactants. As a result, the photocatalytic H2 evolution rate of B–CN reached 268.9 μmol g?1 h?1, over 5 times more than that of bulk C3N4. The Ni ions were further deposited on B–CN as a cocatalyst to enhance the photocatalytic activity. Benefit from the synergy of 2D bubble-like structure and Ni species cocatalyst, recombination of photoinduced charges was greatly inhibited and the hydrogen evolution reaction (HER) was significantly accelerated. The resulted catalyst achieved a dramatically high H2 evolution rate of 1291 μmol g?1 h?1. This work provides an alternative way to synthesize novel porous carbon nitride together with non-noble metal cocatalysts toward enhanced photocatalytic activity for H2 production. 相似文献
18.
《International Journal of Hydrogen Energy》2022,47(67):28845-28858
Photocatalytic water splitting to produce hydrogen (H2), as one means to solve environmental pollution and energy shortage, is limited by the serious recombination of photogenerated electrons and holes, resulting in low solar energy conversion efficiency. Thus, steering the behaviors of charge carriers by rationally designing their transport pathway is essential, which can effectively suppress the recombination of electrons and holes. Herein, we designed a MoS2/TiO2 heterojunction with different vacancy species to manage the migration paths of photogenerated charge carriers. As demonstrated by experimental characterizations and density functional theory (DFT) calculations, oxygen and sulfur vacancies can induce defect energy levels in heterostructures, which can capture photogenerated holes and electrons, respectively, resulting in substantially promoted charge separation efficiency and longer lifetime of electrons. As expected, the optimized photocatalyst shows a stable H2 production rate of 1.41 mmol g?1 h?1, which is significantly better than that of the bare MoS2/TiO2 heterojunction. This finding informs the significance in rational design of the nanostructures for promoting the photocatalytic performance. 相似文献
19.
《International Journal of Hydrogen Energy》2022,47(22):11520-11527
A series of SnS2/ZnIn2S4 (x-SS/ZIS) photocatalysts with different mass ratios of SnS2 were prepared by a hydrothermal method. The resulted composites were used for photocatalytic hydrogen evolution under visible light excitation. All the SS/ZIS composites exhibited significantly enhanced photocatalytic activity for H2 evolution. Obviously, the highest H2 evolution rate of 769 μmol g?1 h?1 was observed over 2.5-SS/ZIS, which was approximately 10.5 times that of the ZnIn2S4 (73 μmol g?1 h?1). The enhanced photocatalytic performance was attributed to the successful construction of SnS2/ZnIn2S4 heterojunctions, leading to rapid charge separation and fast transfer of the photo-generated electrons and holes under light irradiation. On the basis of PL, electrochemical impedance spectroscopy (EIS), photocurrent measurements and the H2 evolution tests, a plausible photocatalytic mechanism was proposed. 相似文献
20.
《International Journal of Hydrogen Energy》2022,47(55):23249-23263
Here, we describe the in-situ synthesis of multicomponent ZnO-based photocatalysts for hydrogen production. We fabricated ZnO coupled with Cu–Cu2O nanoparticles and modified reduced graphene oxide (mRGO) to ameliorate hydrogen production. The simultaneous introduction of mRGO and Cu–Cu2O enhanced the generation rate of photocatalytic hydrogen to 3085.02 μmol g?1 h?1 due to significant alteration of the electronic structure. The bandgap energy of the prepared catalysts decreased from 3.2 eV for pristine ZnO to 2.64 eV for a composite containing 15% Cu–Cu2O. The optimal designed heterostructure efficiently separates photo charge carriers and prevents charge carriers’ recombination by accelerating charge transfer with the help of mRGO and metallic Cu and as a result leading to efficient hydrogen yields. 相似文献