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The cross-sectional area of a surge tank (CAST) is a key factor for protecting pipelines from harm by hydraulic transients. However, for long-distance pipeline systems (LDPS), the water level fluctuations in the surge tank and valve closure water hammer normally share a coupling relationship. Traditionally, this coupling relationship renders difficulty in determining the CAST. This study focused on the influence of water level fluctuation and water hammer, and proposed a simplified approach for sizing surge tanks. First, a water hammer formula that considers the coupling effect was derived. Subsequently, formulae for sizing the CAST were deduced. Finally, a case study of an actual LDPS was conducted to verify the accuracy of the presented formulae. In addition, the calculation errors caused by the theoretical assumptions are discussed. The results indicate that the theoretical calculation values and time-domain simulation results match well, thereby demonstrating the great convenience of designing surge tanks. [ABSTRACT FROM AUTHOR]

The use of photocatalysis and photoelectrocatalysis is expected to achieve the efficient utilization of solar energy to alleviate and even solve the problems of energy depletion and environmental pfollution. At present, stannous tungstate materials have attracted extensive attention in the fields of photocatalysis and photoelectrocatalysis as favorable candidates for such utilization because of their narrow band gap energy (which is ~1.7 eV for the α phase and ~2.7 eV for the β phase, respectively) and unique band structure (which covers the oxidation and reduction potential of water). However, their practical application is still limited by excessive electron–hole recombination and poor stability. In this review, basic information (crystal and electronic structures) related to photocatalysis and photoelectrocatalysis is presented. Additionally, various strategies to enhance the photocatalytic and photoelectrochemical properties of stannous tungstate materials, such as morphological modification, crystal facet engineering, doping modification, and multicomponent compositing, are summarized. Furthermore, the achievements and difficulties of the relevant studies are discussed. The information presented in this review can provide a reference for subsequent research on the photocatalytic and photoelectrochemical performance of tungstate-based materials. [ABSTRACT FROM AUTHOR]

The ever-growing over-consumption of fossil fuels and the accompanying massive emissions of CO2 have caused a severe energy crisis and environmental issues. Photoelectrochemical (PEC) reduction of CO2 that can combine and optimize the merits of both photocatalysis and electrocatalysis has been considered as an attractive prospect for addressing the two problems. Herein, photocathode materials are cores of PEC CO2 reduction. Among various photocathodes, Cu-based photocathodes attract much attention due to their low toxicity, low cost, earth-abundant properties, appropriate range of bandgap values and favorable band edges for CO2 reduction. More to the point, Cu-based photocathodes possess unique advantages for hydrocarbon production such as CO, HCOOH, CH4 or, more importantly, C2 products (like C2H4, C2H5OH and C2H6) compared with other metallic-based photoelectrodes. An insight into the relationships between the properties and functions of photocathodes plays a vital role in the field of PEC CO2 reduction. This review presents the development of Cu-based photocathode materials and discusses future research directions. The photocathode systems mainly include Cu-based oxides, Cu-based chalcogenides and Cu-based electrocatalyst coupled photocathodes. Subsequently, the existing major advantages and disadvantages of each system are also discussed. In conclusion, combining our analyses of the reported photocathodes, we will offer future challenges for the rational design of photoelectrodes. Overall, this review will present a significant overview of Cu-based photocathodes for PEC reduction of CO2. [ABSTRACT FROM AUTHOR]

Electrochemical doping is a promising method to modify the photoelectrochemical performance of semiconductors. The published works using H ions as compensated cations have shown increased photocurrents, but theories vary about the causes of the improvement of photoelectrochemical performance. In this paper, we present the effects of cation ion and the key factors of enhancement using alkali sulfates ((Li/Na/K) 2 SO 4) as the electrolyte for electrochemical doping. The effective electrode surface area (ECSA) was increased for the WO 3 film after electrochemical doping. The Li-ion, with the smallest radius and thereby the highest potential to insert into the WO 3 cell, results in the Li ion inserted WO 3 with the highest photocurrent in the three electrochemically doped samples. To investigate the possible factors affecting the photoelectrochemical performance, the electrochemically doped samples and a control sample were annealed under inert gas (Ar). The lower photocurrents were observed for the electrochemically doped samples after annealing, confirming that the key factors are the increase of the effective electrode surface area caused by electrochemical doping and ion compensation, rather than the ions themselves and the chemical bonds between alkali ions and W or O. Image 1 • Electrochemical doping was performed for WO 3 particle based film. • Enhanced photoelectrochemical activity was gained after treatment. • The effect of cations for electrochemical doping was studied. • Inserted model (Li) shows better performance than the absorption model (K) or complex model (Na). [ABSTRACT FROM AUTHOR]

Reliable manipulation of gaseous bubbles in aqueous media has spurred considerable research interest in recent years due to the tremendous potential ranging from water treatment, catalytic reactions to resource exploration and liquid medicine transportation. However, facile and effective manufacture of functional devices for bubble manipulation is still in great demand. Here, a versatile integrated femtosecond laser-assisted ablation and nanoparticles deposition (FLAND) approach is proposed to obtain Janus organic membranes having mesoscale pore arrays for unidirectional transportation of underwater bubbles. Selective silica nanoparticles deposition occurs simultaneously with laser ablation, enabling superaerophilic/superaerophobic Janus membranes without toxic chemical treatment and rigorous bonding. The FLAND method is capable of controlling the wettability of the pore channel, which is revealed to play a crucial role in the bubble penetration behavior. Analogous to an electrical diode, underwater unidirectional penetration of bubbles is demonstrated for gas-related implementations. This fabrication system with an identical femtosecond laser for simultaneous ablation and nanoparticles deposition manifests simplicity and versatility, opening up more possibilities in manufacturing functional surfaces for various applications. [ABSTRACT FROM AUTHOR]

Abstract: Development of tunable microlenses by taking advantage of the physical adaptability of fluids is one of the challenges of optofluidic techniques, since it offers many applications in biochips, consumer electronics, and medical engineering. Current optofluidic tuning methods using electrowetting or pneumatic pressure typically suffer from high complexity involving external electromechanical actuating devices and limited tuning performance. In this paper, a novel and simple tuning method is proposed that changes the liquid refractive index in an optofluidic channel while leaving the shape of the microlens unchanged. To create an optofluidic microlens with high robustness and optical performance, built‐in microlenses are fabricated inside 3D glass microfluidic channels by optimized single‐operation wet etching assisted by a femtosecond laser. Tuning of focusing properties is demonstrated by filling the channel with media having different indices. Continuous tuning over a wide range (more than threefold tunability for both focal length and focal spot size) is also achieved by pumping sucrose solutions with different concentrations into the microchip channels. Reversible tuning is experimentally verified, indicating intriguing properties of the all‐glass optofluidic microchip. Both the proposed tuning method and the all‐glass architecture with built‐in microlens offer great potential toward numerous applications, including microfluidic adaptive imaging and biomedical sensing. [ABSTRACT FROM AUTHOR]

α-SnWO 4 is a promising semiconductor for solar water splitting, however, its performance is limited by weak water oxidation and poor charge transfer. In this study, we employ a vapor deposition method to uniformly implement a carbon layer onto the surface of SnWO 4 coupled with a CoNiP cocatalyst, successfully constructing the integrated CoNiP/C/SnWO 4 film photoanode and alleviating the oxidation of Sn 2+ when loading electrocatalyst. Incorporating the carbon layer enhances the interface charge conduction behavior between the SnWO 4 substrate and the CoNiP cocatalyst, thereby mitigating charge recombination. The synergistic interplay between the carbon layer and CoNiP leads to a remarkable achievement, as evidenced by the photocurrent of 1.72 mA cm -2 (1.23 V vs. RHE) observed for SnWO 4 film measured in 0.2 M potassium phosphate buffer solution. In this work, we demonstrate the viability of tailoring SnWO 4 photoanode and provide valuable insights for prospective advancements in modifying SnWO 4 photoanode., (© 2024 Wiley-VCH GmbH.)

The low solubility of CO 2 molecules and the competition of the hydrogen evolution reaction (HER) in aqueous electrolytes pose significant challenges to the current photoelectrochemical (PEC) CO 2 reduction reaction. In this study, inspired by the bilayer phospholipid molecular structure of cell membranes, we developed a Cu 2 O/Sn photocathode that was modified with the bilayer surfactant DHAB for achieving high CO 2 permeability and suppressed HER. The Cu 2 O/Sn/DHAB photocathode stabilizes the *OCHO intermediate and facilitates the production of HCOOH. Our findings show that the Faradaic efficiency (FE) of HCOOH by the Cu 2 O/Sn/DHAB photoelectrode is 83.3%, significantly higher than that achieved with the Cu 2 O photoelectrode (FE HCOOH = 30.1%). Furthermore, the FE H2 produced by the Cu 2 O/Sn/DHAB photoelectrode is only 2.95% at -0.6 V vs RHE. The generation rate of HCOOH by the Cu 2 O/Sn/DHAB photoelectrode reaches 1.52 mmol·cm -2 ·h -1 ·L -1 at -0.7 V vs RHE. Our study provides a novel approach for the design of efficient photocathodes for CO 2 reduction.

The limited mass transfer of CO 2 and the competitive hydrogen evolution reaction (HER) during photoelectrochemical (PEC) CO 2 reduction usually result in low CO 2 reduction activity. Here, we constructed a Cu 2 O/Sn/PTFE photocathode with a hydrophobic surface based on Cu 2 O by physical vapor deposition and a dipping method. The CO faradaic efficiency (FE) increased from 34.5% (Cu 2 O) to 95.1% (Cu 2 O/Sn/PTFE) at -0.7 V vs. RHE, and the FE H2 decreased from 27.9% (Cu 2 O) to 3.8% (Cu 2 O/Sn/PTFE). The introduction of the hydrophobic layer enhances the local CO 2 concentration on the electrode surface and effectively isolates H + from the aqueous electrolyte, thereby enhancing the CO 2 reduction activity.

Hydrogen generation through photoelectrochemical (PEC) technology is one of the most appropriate ways for delivering sustainable fuel. Simultaneously, anisotropic properties will be exhibited by the materials with low crystal symmetry, allowing the tuning of the PEC properties by controlling the crystallographic orientation and exposed facets. Therefore, we synthesized copper tungstate films (CuWO 4 ) with highly exposed (100) crystal facets by regulating anions in the precursor solution. According to experimental characterization and density functional theory calculations, the CuWO 4 film with a high exposure ratio of the (100) crystal facet has promoted charge transport with trap-free mode and reduced recombination of electrons and holes. Meanwhile, the oxygen evolution reaction is promoted on the (100) facet because of the relatively low energy barrier. Compared to the CuWO 4 with other mixed exposure facets, CuWO 4 with a highly exposed (100) facet presents a twofold current density (0.38 mA/cm 2 ) and one-fifteenth electron transit time (0.698 ms) and also has great stability (more than 6 h). These results provide an easy way to enhance the PEC performance by modulating the exposure facets of the film electrode.