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In this paper, a novel maximum likelihood sequence estimation (MLSE) optimum receiver design is proposed to reduce the complexity of the conventional optimum receiver. We first propose a multipath channel classification method according to the zero distribution of the channel impulse response; that is, the multipath channel is divided into a minimum phase channel and a non-minimum phase channel. Then, an MLSE optimum receiver design with channel identification based on zero distribution is also proposed. In this design, the distribution of zero can be obtained directly by calculating the Z transform of the channel. Thus, the complexity is reduced. The number of the multiplication reduced is N (2 N + 1) . In addition, 2 N + 1 memory units storing the autocorrelation sequence are reduced. The simulation results indicate that this channel classification method effectively represents the characteristics of the channel. Moreover, the MLSE optimum receiver proposed performs similarly and is less complex than the conventional one. The performance is greatly improved compared with the minimum mean square error (MMSE) equalizer. [ABSTRACT FROM AUTHOR]

Photo‐rechargeable zinc‐ion batteries (PRZIBs) have attracted much attention in the field of energy storage due to their high safety and dexterity compared with currently integrated lithium‐ion batteries and solar cells. However, challenges remain toward their practical applications, originating from the unsatisfactory structural design of photocathodes, which results in low photoelectric conversion efficiency (PCE). Herein, a flexible MoS2/SnO2‐based photocathode is developed via constructing a sunflower‐shaped light‐trapping nanostructure with 3D hierarchical and self‐supporting properties, enabled by the hierarchical embellishment of MoS2 nanosheets and SnO2 quantum dots on carbon cloth (MoS2/SnO2 QDs@CC). This structural design provides a favorable pathway for the effective separation of photogenerated electron‐hole pairs and the efficient storage of Zn2+ on photocathodes. Consequently, the PRZIB assembled with MoS2/SnO2 QDs@CC delivers a desirable capacity of 366 mAh g−1 under a light intensity of 100 mW cm−2, and achieves an ultra‐high PCE of 2.7% at a current density of 0.125 mA cm−2. In practice, an integrated battery system consisting of four series‐connected quasi‐solid‐state PRZIBs is successfully applied as a wearable wristband of smartwatches, which opens a new door for the application of PRZIBs in next‐generation flexible energy storage devices. [ABSTRACT FROM AUTHOR]

As a visible-light response semiconductor materials, bismuth vanadate (BiVO4) is extensively applied in photodegradation organic dye field. In this study, we synthesized C3N5 nanosheets and coupled with decahedral BiVO4 to construct a Z-scheme C3N5/BiVO4 heterostructure with close interface contact. By introducing C3N5 into BiVO4, the built Z-scheme transfer pathway provides silky channel for charge carrier migration between different moieties and enables photoexcited electrons and holes accumulated on the surface of BiVO4 and C3N5. The accelerated separation of charge carriers ensures C3N5/BiVO4 heterostructures with a powerful oxidation capacity compared with pure BiVO4. Due to the synergistic effect in Z-scheme heterostructure, the C3N5/BiVO4 demonstrated an improved photodegradation ability of rhodamine B (RhB) and methylene blue (MB) that of bare BiVO4. [ABSTRACT FROM AUTHOR]

The effective utilization of the local surface plasmon resonance (LSPR) effect of metal nanoparticles to improve optical absorption capacity and inject hot electrons into photocatalysts opens up new directions and ideas to solve the problem of solar energy utilization efficiency of photocatalysts. In this study, we created an in situ technique for preparing plasmon Ag nanoparticles (NPs) decorated with a covalent organic framework (COF), named Ag/TpPa-1-COF. The LSPR effect of Ag NPs results in an outstanding rate of H2 production that is 801.4 μmol g−1 h−1 for the 3% Ag/TpPa-1 photocatalyst, which is almost 4 times as effective as that of the unmodified TpPa-1-COF. Moreover, finite-difference time-domain (FDTD) simulation results reveal that the strongest electric field intensity is presented when the catalyst is excited at λ = 465 nm. Furthermore, plasmonic "hot spots" induced by the interfacial electric field enhancement factor distribution of Ag/TpPa-1 were simulated in detail by adjusting the number, particle size, and gap distance of Ag NPs. Additionally, density functional theory (DFT) calculations show that electron transfer from Ag NPs to TpPa-1 occurs at the Ag/TpPa-1 interface, and N sites in Ag/TpPa-1 exhibit low Gibbs free energy (ΔGH*) for enhanced photocatalytic H2 evolution. Overall, this research provides new insights into the plasmonic "hot spot" region that performs effectively for hydrogen evolution. [ABSTRACT FROM AUTHOR]

A dispersion containing black TiO2 photocatalyst was prepared and sprayed onto the concrete's surface to achieve a black TiO2-based photocatalytic concrete paving eco-block, and its photocatalytic NO removal ratio is approximately 1.7 times as high as that of a white TiO2-based eco-block, resulting from the enhanced optical absorption intensity, abundant oxygen vacancies, and highly produced superoxide anion radicals (˙O2−) of black TiO2. Moreover, the black TiO2-based concrete paving eco-block exhibits significantly enhanced compressive strength and abrasion resistance when using water-glass as a binder, which could satisfy the demand for practical application. Furthermore, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was performed to dynamically track the reactive products and intermediates across the surface of the B-TiO2 photocatalyst in a time sequence to investigate the reaction mechanism. It has been demonstrated that almost no harmful by-products were produced when NO was removed via photocatalysis, and the applicability of the as-prepared eco-blocks was evaluated considering the effects of various reaction conditions. Additionally, a computational fluid dynamics (CFD) model for solar-driven photocatalytic abatement of atmospheric NO in a realistic urban street coating with black TiO2-based photocatalytic concrete paving eco-blocks was constructed and simulated to assess the real-world applicability of the developed approach. Overall, this research may offer fresh perspectives on how to create ecologically acceptable photocatalytic products for the removal of air pollutants using solar light. [ABSTRACT FROM AUTHOR]

In this study, Pt-M/WO3 (M = Cu, Co, and Ni) thin films are effectively synthesized by preparing homogeneous precursor sols, spin-coating, toluene-etching, and calcination. Furthermore, the microstructural, chemical, and electrochemical properties of the WO3, Pt-Cu/WO3, Pt-Co/WO3, and Pt-Ni/WO3 thin films are also systematically compared. The results demonstrate that when compared to the WO3 thin film, the photocatalytic capability for methylene blue (MB) solution degradation is greatly increased in the Pt-M/WO3 thin films. Transfer routes for photogenerated charges and an improved photocatalytic process are suggested based on the experimental results. Due to the large difference in the work function (Φ) between the bimetallic alloy Pt-M and WO3, a bending of the energy bands at the Pt-M/WO3 interface is presented. Furthermore, the introduction of transition metals such as Cu, Co, or Ni modifies the electronic structure of Pt-M/WO3 thin films, facilitating the separation and migration of electrons and holes. Specifically, the photogenerated electrons migrate from the CB of WO3 to Pt-Co or Pt-Ni nanoparticles in the samples of Pt-Co/WO3 or Pt-Ni/WO3 thin films, while the hot electrons from the localized surface plasmon resonance (LSPR) effect of Cu could transfer to the conduction band (CB) of WO3 and other electrons generated from the photoexcitation of the WO3 semiconductor itself in the sample of the Pt-Cu/WO3 thin film. In summary, this work proposes a unique strategy for creating electron regulation in Pt-M decorated WO3 thin films for photocatalytic application. [ABSTRACT FROM AUTHOR]

It has been rarely reported the morphological control of derivatives of metal‐organic frameworks (MOFs) in hydrothermal conditions for photocatalytic applications. We report here a family of highly efficient composite photocatalysts composed of terephthalic acid/terephthalate (TPA) ligand and TiO2 with various morphologies (e. g. nanoparticles, nanosheets, and nanorods). The composites are synthesized by a simple one‐step hydrothermal method in various solvents (i. e. H2O, HF, H2SO4, HCl, and HNO3) using Ti‐based MOF (MIL‐125(Ti)) as precursor. The formation mechanism of composite materials with different morphological features is discussed. Impressively, the composite of TiO2 nanoparticles/TPA synthesized using H2O as solvent under hydrothermal condition exhibits the highest photocatalytic H2 activity among the studied materials, with a photocatalytic H2 production rate of 6.38 mmol g−1 h−1, which is approximately 7.5‐fold higher than pure TiO2 (Degussa, P25) and prominent apparent quantum efficiency (AQE) of 65 % at 365 nm. Furthermore, the mechanism of boosted photocatalytic H2 production is discussed. [ABSTRACT FROM AUTHOR]

Summary: In this paper, the channel estimation and signal‐to‐noise ratio (SNR) estimation technique of single‐carrier frequency domain equalization (SC‐FDE) system under low SNR in aeronautical multipath channel are studied, a SNR estimation algorithm which is easy to implement in engineering and an improved LS channel estimation algorithm based on Kalman filter using minimum error entropy (MEE‐KF) are proposed. This paper first introduces the SC‐FDE system and introduces the principle of MEE‐KF, and then, the channel estimation flow based on MEE‐KF is obtained by combining it with the traditional LS channel estimation algorithm, which makes the estimation results perform better. Simulation results show that after getting more accurate noise variance, the channel estimation results can better follow the changes of the channel after MEE‐KF processing, so as to resist the doppler frequency offset effect and make the channel estimation results more accurate, that is the channel response results of the data part can be closer to the real situation, so that the communication performance of SC‐FDE system has also been greatly improved. [ABSTRACT FROM AUTHOR]