查找使用阿拉丁产品的科研文献

One-step synthesis of PPyNT/NiOx nanocomposites via microwave method and application for supercapacitor

Huijun Liu,Qiang Zhao,Kewei Wang,Zhen Lu,Feng Feng,Yong Guo

In this study, PPyNT/NiOx nanocomposites were synthesized by simple and fast microwave method. Samples were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and Scanning electron microscopy (SEM). Furthermore, synthesized PPyNT/NiOx nanocomposites were electrochemically characterized using galvanostatic charge/discharge, cyclic voltammetry, and electrochemical impedance spectroscopy techniques. Results showed the highest specific capacitance of 192 F g−1 at 1 A g−1, which is significantly higher than that of pristine PPyNT (106 F g−1 at 1 A g−1). Surprisingly, the specific capacitance could be further increased by 158% (304 F g−1 at 1 A g−1) after 480 cycles. The cycling stability with nearly 100% of the initial capacitance value over 2000 cycles at 1 A g−1. The composite electrode material has great promise to achieve large-scale industrial production for supercapacitors. Moreover, the asymmetric supercapacitor device based on the PPyNT/NiOx//active carbon showed a maximum gravimetric energy density of 10.74 Wh kg−1 and power density of 0.19 kW kg−1.

Bifunctional NiOx/Perovskite Interface Engineering for Efficient Air-Processed Wide-Bandgap Perovskite Solar Cells

Zhu Ying,Zhang Xin,Geng Yuwei,Liu Yan,Yang Guanjun,Chen Bo

Nickel oxide (NiO x ) hole transport layers are widely employed in perovskite solar cells (PSCs) due to their excellent chemical stability. However, the poor quality of the NiO x /perovskite interface limits device performance. Herein, we report a bifunctional interface engineering strategy using ammonium thiocyanate (NH 4 SCN) that reduces energy barriers and passivates defects at the NiO x /perovskite interface. NH 4 SCN decreases surface hydroxyl groups on NiO x , suppresses trap states, and improves energy-level alignment of hole transport layer with perovskite. Additionally, NH 4 SCN promotes the growth of larger perovskite grains, alleviates lattice strain, and passivates defects at buried interface of perovskite film, thus enhancing film quality and improving carrier lifetime. As a result, air-processed wide-bandgap PSCs based on NH 4 SCN-treated NiO x achieve a power conversion efficiency of 21.41% and an open-circuit voltage of 1.260 V, outperforming control devices (19.81%, 1.236 V). This work provides an effective interface engineering strategy for high-performance wide-bandgap PSCs.

Structural Modulation of Pt Nanoparticles Anchored by NiOx on Silica for Enhanced Methylcyclohexane Dehydrogenation

Gang Hou,Bofeng Zhang,Liming Xia,Mingxia Song,Guozhu Liu

Liquid organic hydrogen carriers represent a promising strategy for advancing the development of hydrogen-based energy systems. However, the catalytic dehydrogenation performance of cycloalkanes on Pt-based catalysts is intrinsically limited by a trade-off between reactant activation and aromatic products desorption. The strongly adsorbed products prove detrimental and require enhancement of desorption without activity loss. Here, we synthesized thermally stable Pt nanoparticles immobilized by uniformly distributed NiOx species on fumed SiO2. For methylcyclohexane dehydrogenation, the stabilizing role of NiOx cluster-modified SiO2 combined with hydrogen-carrier-gas-assisted toluene desorption ensured the long-term stability of Pt nanoparticles. Furthermore, the optimized NiOx–Pt interaction generated partially positively charged Pt species, facilitating C–H activation. The synthesized PtNi1/SiO2 exhibited a hydrogen production rate of 58.9 mmolH2 gcat–1 min–1 with high toluene selectivity (>99%) at 350 °C. It remained stable for over 2400 min through intermittent regeneration under a high weight hourly space velocity of 50 h–1. This work demonstrates the rational design of thermally stable metal nanoparticles and provides mechanistic insights into suppressing dehydrogenation and catalyst deactivation.

High-efficiency perovskite nanocrystal light-emitting diodes via decorating NiOx on the nanocrystal surface

Weilin Zheng,Qun Wan,Qinggang Zhang,Mingming Liu,Congyang Zhang,Bo Wang,Long Kong,Liang Li

Nickel oxides exhibit a great potential as hole transport layers for the fabrication of efficient perovskite light-emitting diodes (LEDs) due to their high carrier mobility and good energy band matching with perovskite nanocrystals. In this work, nickel oxides were directly decorated on the CsPbBr3 nanocrystal surface through adsorption and a sequential oxidation treatment. The resulting sample shows a high photoluminescence quantum-yield of 82%. The LED using CsPbBr3 nanocrystals with nickel oxides achieves a high external quantum efficiency (EQE) of up to 16.8% with a low turn-on voltage of 2.8 V, which is much superior to that of the counterpart LED based on pristine CsPbBr3 nanocrystals (EQE = 0.7%, turn-on voltage = 5.6 V). The excellent performance of the nickel oxide decorated CsPbBr3 nanocrystal device could be attributed to the better energy level matching between the decorated nanocrystals and the transport layers of the device and more balanced charge carrier injection. Furthermore, the operational lifetime of the nickel oxide decorated CsPbBr3 nanocrystal device is 40 times longer than that of the pristine CsPbBr3 nanocrystal device.

Synergetic Interface and Bulk Defects Modification with Identical Organic Molecule for Efficient Inverted Perovskite Solar Cells

Junbo Yang,Zhu Ma,Wei You,Yi Chen,Zhuowei Du,Shenshen Zheng,Qiang Yang,Hao Du,Qian Zhang,Yixian Li,Fuchun Gou,Bo Chen,Zhuo Lv,Kai Liu,Hong Yu,Yan Xiang,Cheng Huang,Jian Yu,Fengying Zhang,Wenfeng Zhang,Kuan Sun,Liming Ding

Recent progress in inverted perovskite solar cells (IPSCs) mainly focused on NiOx modification and perovskite (PVK) regulation to enhance efficiency and stability. However, most works address only monofunctional modifications, and identical molecules with the ability to simultaneously optimize NiOx interface and perovskite bulk phase have been rarely reported. This work proposes a dual modification approach using 4-amino-3,5-dichlorobenzotrifluoride (DCTM) to optimize both NiOx upper interfaces and reduction of bulk defects in perovskite. Amino group in DCTM increases the Ni3+/Ni2+ ratio in NiOx, thereby increasing the conductivity and optimizing the energy alignment. Additionally, DCTM fills Pb2+ and I– vacancies in perovskite, which improves the vertical orientation of perovskite grains and subsequently reduces nonradiative recombination, thereby achieving the increased carrier lifetime. PVK modified by DCTM exhibits enhanced energy level alignment with the electron transport layer, while femtosecond transient absorption (TA) spectroscopy confirms that DCTM facilitates efficient carrier transport, leading to high-performance IPSCs. The optimized IPSCs achieve a maximum efficiency of 22.8% with a reduced hysteresis (0.7%). Moreover, the unencapsulated device preserves over 80% of its initial power conversion efficiency (PCE) after 1000 h stored in air at 30% relative humidity. This dual modification strategy of monomolecular offers a straightforward solution for interface optimization and provides new insights into selecting aniline-derived molecules for high-performance IPSCs.

Interfacial Dipole Engineering for Energy Level Alignment in NiOx-Based Quantum Dot Light-Emitting Diodes

Shuai-Hao Xu,Jin-Zhe Xu,Ying-Bo Tang,Wei-Zhi Liu,Shu-Guang Meng,Dong-Ying Zhou,Liang-Sheng Liao

The solution-derived non-stoichiometric nickel oxide (NiO x ) is a promising hole-injecting material for stable quantum dot light-emitting diodes (QLEDs). However, the carrier imbalance due to the misalignment of energy levels between the NiO x and polymeric hole-transporting layers (HTLs) curtails the device efficiency. In this study, the modification of the NiO x surface is investigated using either 3-cyanobenzoic acid (3-CN-BA) or 4-cyanobenzoic acid (4-CN-BA) in the QLED fabrication. Morphological and electrical analyses revealed that both 4-CN-BA and 3-CN-BA can enhance the work function of NiO x , reduce the oxygen vacancies on the NiO x surface, and facilitate a uniform morphology for subsequent HTL layers. Moreover, it is found that the binding configurations of dipole molecules as a function of the substitution position of the tail group significantly impact the work function of underlying layers. When integrated in QLEDs, the modification layers resulted in a significant improvement in the electroluminescent efficiency due to the enhancement of energy level alignment and charge balance within the devices. Specifically, QLEDs incorporating 4-CN-BA achieved a champion external quantum efficiency (EQE) of 20.34%, which is a 1.8X improvement in comparison with that of the devices utilizing unmodified NiO x (7.28%). Moreover, QLEDs with 4-CN-BA and 3-CN-BA modifications exhibited prolonged operational lifetimes, indicating potential for practical applications.

Interface Defects Dependent on Perovskite Annealing Temperature for NiOX-Based Inverted CsPbI2Br Perovskite Solar Cells

Zhaoxuan Huang,Nan Tian,Shiyu Duan,Jicheng Zhang,Disheng Yao,Guoyuan Zheng,Yanhan Yang,Bing Zhou

Nickel oxide (NiOX) is an ideal inorganic hole transport material for the fabrication of inverted perovskite solar cells owing to its excellent optical and semiconductor properties. Currently, the main research on developing the performance of NiOX-based perovskite solar cells focuses on improving the conductivity of NiOX thin films and preventing the redox reactions between metal cations (Ni3+ on the surface of NiOX) and organic cations (FA+ or MA+ in the perovskite precursors) at the NiOX/perovskite interface. In this study, a new type of interface defects in NiOX-based CsPbI2Br solar cells is reported. That is the Pb2+ from CsPbI2Br perovskites can diffuse into the lattice of NiOX surface as the annealing temperature of perovskites changes. The diffusion of Pb2+ increases the ratio of Ni3+/Ni2+ on the surface of NiOX, leading to an increase in the density of trap state at the interface between NiOX and perovskites, which eventually results in a serious decline in the photovoltaic performance of solar cells.

NiOx/SAM-Mediated Interface Engineering for High-Performance PEA2SnI4 Pure-Red Perovskite Light-Emitting Diodes

Jiaxing Zhu,Qi Xiao,Renqiang Yang,Jiajun Luo,Jiang Tang

Tin-based perovskite light-emitting diodes (PeLEDs) have emerged as promising candidates for environmentally benign optoelectronic applications. However, their practical performance remains limited by severe interfacial defect states, particularly at the buried interface. In this work, we introduce a self-assembled monolayer (SAM) molecule [4-(3,6-dibromo-9H-carbazol-9-yl)butyl]phosphonic acid (Br-4P), combining NiOx to effectively mitigate interfacial defects for PEA2SnI4-based (PEA = phenethylammonium) pure-red PeLEDs. This SAM is meticulously designed with tailored dimensions to achieve interfacial structural synergy with PEA2SnI4, serving as a bridging component between NiOx and the perovskite. The insertion of Br-4P promotes superior crystallinity and more uniform crystal orientation, enables the passivation of undercoordinated Sn2+ species, and the phosphate group of Br-4P functions to anchor onto NiOx. As a result, the optimized PeLEDs achieved a peak external quantum efficiency of 6.19% at 623 nm with a narrow full width at half-maximum of 27 nm and a luminance of 226 cd·m–2. This work highlights the critical role of interface engineering in unlocking the potential of Sn-based perovskite emitters for high-efficiency, nontoxic light-emitting applications.

Bimolecular Passivation Layer Modified NiOx to Improve the Efficiency and Stability of Perovskite Solar Cells

Wentao Ma,Xu Ren,Jinxi Wang,Xiao Tan,Mengshuan Cui,Kai Liu,Huixian Ren,Jiamei Liu,Hanying Wang,Xiaoyan Xi,Shiqing Bi

NiOx as a hole transport layer (HTL) for inverted perovskite solar cells (PSCs) shows significant commercialization prospects for enhancing device efficiency. However, limited by the problem of defects at the interface between perovskite and NiOx, achieving effective interfacial passivation still faces many challenges. In this study, Me-4PACz is doped with potassium 4-chlorophenyl trifluoroborate (PCPTFB) to form a co-self-assembled monolayer (Co-SAM) to modify the buried interface of PSCs. The system effectively passivates NiOx surface defects by PCPTFB, optimizes the Ni3+/Ni2+ ratio, enhances the hole extraction capability, and improves the energy band matching. In addition, PCPTFB synergistically stabilized the perovskite interface, reduced nonradiative recombination, and promoted the formation of high-quality perovskite films. Based on the above optimization, the Me-4PACz+PCPTFB modified device achieved an excellent photoelectric conversion efficiency (PCE) of 23.68%. For the stability test, the unencapsulated PSCs maintained an initial efficiency of 90% after 1400 h of aging in a nitrogen environment, demonstrating excellent long-term stability. This innovative strategy not only highlights the important role of Me-4PACz+PCPTFB in NiOx/perovskite interfacial engineering but also provides a new technological path to realize efficient and stable PSCs.

High-Performance Inverted Perovskite Solar Cells with Mesoporous NiOx Hole Transport Layer by Electrochemical Deposition

Tun Wang,Dong Ding,Xin Wang,Ranran Zeng,Hong Liu,Wenzhong Shen

Perovskite solar cells (PSCs) based on a NiOx hole transport layer (HTL) with an inverted p–i–n configuration have yielded highly efficient and relatively stable devices. Here, we develop a simple electrochemical deposition method for quickly and evenly preparing a mesoporous NiOx film. It is demonstrated that the increasing thickness and decreasing surface roughness of the NiOx film are beneficial for light transmission. The optimal condition for preparing NiOx films is achieved by adjusting the deposition time at a certain applied current density, which exhibits excellent optical transmittance and suitable thickness and band gap, thus reducing optical loss and enhancing hole extraction at the interface between HTL and the perovskite layer and therefore improving photovoltaic performances. The finite-difference time-domain simulation confirms the optimal thickness of the NiOx layer and coincides with our experiment results. An optimal power conversion efficiency (PCE) of 17.77% with an active area of 0.25 cm2 is achieved. The prepared device shows negligible hysteresis, high reproducibility, and high uniformity with a PCE difference of 2% for measuring the different sites from edge to center. This simple fabrication process paves a novel way to the evolution of PSCs based on NiOx and rapid commercialization.

Non-Noble Metal Ni/NiOx@C Co-Catalyst Modified ZnIn2S4 for Efficient Photocatalytic Hydrogen Production

Photocatalytic hydrogen production has emerged as one of the most promising approaches for addressing the global energy crisis by enabling the sustainable conversion of solar energy into clean hydrogen fuel. However, its practical application is still hindered by the rapid recombination of photogenerated electron–hole pairs, which severely limits photocatalytic efficiency. Although noble-metal co-catalysts have been demonstrated to markedly promote charge separation and accelerate surface reaction kinetics, their widespread application remains constrained by their high cost and limited availability. In this study, a non-noble Ni/NiOx@C co-catalyst was fabricated and employed to modify ZnIn2S4(ZIS) for photocatalytic hydrogen production. The optimized sample (15Ni/NiOx@C/ZIS) exhibits a hydrogen production rate of 4140.03 μmol/g/h, 18.16 times higher than that of pristine ZIS. This enhancement is primarily attributed to the improved separation and transfer of photogenerated charge carriers facilitated by the Ni/NiOx@C co-catalyst. Notably, the hydrogen evolution rate of 15Ni/NiOx@C/ZIS is 1.33 times higher than that of ZIS/3%Pt, suggesting that Ni/NiOx@C has great potential as a substitute for noble metal Pt. Various characterization results demonstrate that 15Ni/NiOx@C/ZIS exhibits superior photocatalytic performance, ascribed to its enhanced light absorption capability, and efficient separation of photogenerated carriers. Additionally, cycling tests and XRD analysis confirm the excellent stability of 15Ni/NiOx@C/ZIS, indicating its potential for practical applications. This work provides a valuable reference for the rational design and development of efficient and cost-effective non-noble co-catalysts for photocatalytic hydrogen production.

Mandelic Acid as an Interfacial Modifier for High Performance NiOx-based Inverted Perovskite Solar Cells

Yu Fu,Xingchong Liu,Shuangshuang Zhao

Graphical Small molecule mandelic acid was introduced for the first time as a modification layer in NiO x and perovskite layers in inverted perovskite solar cells. The MAD modified layer can not only reduce the roughness of the NiOx hole transport layer but also interact with the unreacted PbI 2 in the perovskite layer. As a result, MAD enhanced the crystallinity of the perovskite and thus the photovoltaic performance of the device was improved Nickel oxide (NiO x ) inverted perovskite solar cells have been witnessed as promising solar cells because of the low cast, easy fabrication and negligible hysteresis. However, the inferior interface feature of the link NiO x and perovskite layer often causes poor device property and repeatability. Here, Mandelic acid (MAD) is introduced to form a modified layer, which could improve the poor interface properties between perovskite layer and NiO x layer. The contact angel images revels MAD could increase the hydrophobicity and facilitate the growth of perovskite crystal. The X-ray diffraction pattern and Fourier transform infrared spectroscopy have confirmed that the MAD small molecule could interact with residual PbI 2 crystal, leading to better interface contact and high crystallinity. This is further demonstrated by the scanning electron microscopy test of NiO x /MAD/MAPbI 3 film that average grain size is increased from 201.85 nm to 315.17 nm. The space-charge limited current measurement proves the introduction of MAD molecule that result in the decreased trap state density from 3.58×10 15 cm −3 to 2.7210 15 cm −3 . As a consequence, The power conversion efficiency is significantly improved from 14.9% to 18.42% of MAPbI 3 -based devices that retained nearly 80% initial PCE after 50 days in N 2 without encapsulation.