Solar‑Driven Sustainability:Ⅲ–ⅤSemiconductor for Green Energy Production Technologies

Long-term societal prosperity depends on addressing the world’s energy and environmental problems,and photocatalysis has emerged as a viable remedy.Improving the efficiency of photocatalytic processes is fundamentally achieved by optimizing the effective utilization of solar energy and enhancing the efficient separation of photogenerated charges.It has been demonstrated that the fabrication ofⅢ–Ⅴsemiconductor-based photocatalysts is effective in increasing solar light absorption,long-term stability,large-scale production and promoting charge transfer.This focused review explores on the current developments inⅢ–Ⅴsemiconductor materials for solar-powered photocatalytic systems.The review explores on various subjects,including the advancement ofⅢ–Ⅴsemiconductors,photocatalytic mechanisms,and their uses in H2 conversion,CO_(2)reduction,environmental remediation,and photocatalytic oxidation and reduction reactions.In order to design heterostructures,the review delves into basic concepts including solar light absorption and effective charge separation.It also highlights significant advancements in green energy systems for water splitting,emphasizing the significance of establishing eco-friendly systems for CO_(2)reduction and hydrogen production.The main purpose is to produce hydrogen through sustainable and ecologically friendly energy conversion.The review intends to foster the development of greener and more sustainable energy source by encouraging researchers and developers to focus on practical applications and advancements in solar-powered photocatalysis.

A Solar Energy System Design for Green Hydrogen Production in South-Western Nigeria, Lagos State, Using HOMER & ASPEN

Solar system design for green hydrogen production has become the most prominent renewable energy research area, and this has also actively fueled the desire to achieve net-zero emissions. Hydrogen is a promising energy carrier because it possesses more energy capacity than fossil fuels and the abundant nature of renewable energy systems can be utilized for green hydrogen production. However, the design of an optimized electrical energy system required for hydrogen production is crucial. Solar energy is indeed beneficial for green hydrogen production and this research designed, discussed, and provided high-level research on HOMER design for green hydrogen production and deployed the energy requirement with ASPEN Plus to optimize the energy system, while also incorporating fuzzy logic and PID control approaches. In addition, a promising technology with a high potential for renewable hydrogen energy is the proton exchange membrane (PEM) electrolyzer. Since its cathode (hydrogen electrode) may be operated over a wide range of pressure, a control process must be added to the system in order for it to work dynamically efficiently. This system can be characterized as an analogous circuit that consists of a resistor, capacitor, and reversible voltage. As a result, this research work also explores the Fuzzy-PID control of the PEM electrolysis system. Both the PID and Fuzzy Logic control systems were simulated using the control simulation program Matlab R2018a, which makes use of Matlab script files and the Simulink environment. Based on the circuit diagram, a transfer function that represents the mathematical model of the plant was created, and the PEM electrolysis control system is determined to be highly significant and applicable to the two control systems. The PI controller, however, has a 30.8% overshoot deficit, but when the fuzzy control system is compared to the PID controller, it is found that the fuzzy control system achieves stability more quickly, demonstrating its benefit over PID.

Electrospun Semiconductor-Based Nano-Heterostructures for Photocatalytic Energy Conversion and Environmental Remediation:Opportunities and Challenges

Harvesting solar energy to drive the semiconductor photocatalysis offers a promising tactic to address ever-growing challenges of both energy shortage and environmental pollution.Design and synthesis of nano-heterostructure photocatalysts with controllable components and morphologies are the key factors for achieving highly efficient photocatalytic processes.Onedimensional(1D)semiconductor nanofibers produced by electrospinning possess a large ratio of length to diameter,high ratio of surface to volume,small grain sizes,and high porosity,which are ideally suited for photocatalytic reactions from the viewpoint of structure advantage.After the secondary treatment of these nanofibers through the solvothermal,gas reduction,in situ doping,or assembly methods,the multi-component nanofibers with hierarchical nano-heterostructures can be obtained to further enhance their light absorption and charge carrier separation during the photocatalytic processes.In recent years,the electrospun semiconductorbased nano-heterostructures have become a“hot topic”in the fields of photocatalytic energy conversion and environmental remediation.This review article summarizes the recent progress in electrospinning synthesis of various kinds of high-performance semiconductor-based nano-heterostructure photocatalysts for H2 production,CO_(2) reduction,and decomposition of pollutants.The future perspectives of these materials are also discussed.

Progress in manipulating spin polarization for solar hydrogen production

Photocatalytic and photoelectrochemical water splitting using semiconductor materials are effective approaches for converting solar energy into hydrogen fuel.In the past few years,a series of photocatalysts/photoelectrocatalysts have been developed and optimized to achieve efficient solar hydrogen production.Among various optimization strategies,the regulation of spin polarization can tailor the intrinsic optoelectronic properties for retarding charge recombination and enhancing surface reactions,thus improving the solar-to-hydrogen(STH)efficiency.This review presents recent advances in the regulation of spin polarization to enhance spin polarized-dependent solar hydrogen evolution activity.Specifically,spin polarization manipulation strategies of several typical photocatalysts/photoelectrocatalysts(e.g.,metallic oxides,metallic sulfides,non-metallic semiconductors,ferroelectric materials,and chiral molecules)are described.In the end,the critical challenges and perspectives of spin polarization regulation towards future solar energy conversion are briefly provided.

Hybridized Mechanical and Solar Energy-Driven Self-Powered Hydrogen Production

Photoelectrochemical hydrogen generation is a promising approach to address the environmental pollution and energy crisis.In this work,we present a hybridized mechanical and solar energy-driven selfpowered hydrogen production system.A rotatory disc-shaped triboelectric nanogenerator was employed to harvest mechanical energy from water and functions as a su cient external power source.WO3/BiVO4 heterojunction photoanode was synthesized in a PEC water-splitting cell to produce H2.After transformation and rectification,the peak current reaches 0.1 m A at the rotation speed of 60 rpm.In this case,the H2 evolution process only occurs with sunlight irradiation.When the rotation speed is over 130 rpm,the peak photocurrent and peak dark current have nearly equal value.Direct electrolysis of water is almost simultaneous with photoelectrocatalysis of water.It is worth noting that the hydrogen production rate increases to 5.45 and 7.27μL min-1 without or with light illumination at 160 rpm.The corresponding energy conversion e ciency is calculated to be 2.43%and 2.59%,respectively.All the results demonstrate such a self-powered system can successfully achieve the PEC hydrogen generation,exhibiting promising possibility of energy conversion.

Analysis Of China＇s New Solar Energy And Hydrogen Energy Industry Trend

Every crisis has meant the decline and death of the old things, but also indicates that the birth of new things and grow. Energy crisis and environmental crisis prompted human thinking, looking for a way out. While fossil energy in the past hundred years time, the development of human society has made a huge role, but due to the limitations of its own： the non-renewable nature, environmental pollution and energy politicized, destined to be replaced. New energy in a tough energy and environmental situation become a new impetus for economic development. Of course, the new energy present due to various reasons, in the proportion of human energy consumption structure, the proportion accounted for far less than fossil fuels, technical issues, storage and transportation issues and cost issues still restrict the development and popularization of new energy. Nuclear, solar, wind, tidal energy and hydrogen energy are all new areas. Which in terms of nuclear and solar energy technology, the use is still relatively mature, the market prospects of other energy sources is also very tempting, in this paper, standing industrial perspective analysis of the market prospects of new energy solar and hydrogen energy.

Recent advances in bismuth-based photocatalysts:Environment and energy applications

Photocatalysis is an effective way to solve the problems of environmental pollution and energy shortage.Numerous photocatalysts have been developed and various strategies have been proposed to improve the photocatalytic performance.Among them,Bi-based photocatalysts have become one of the most popular research topics due to their suitable band gaps,unique layered structures,and physicochemical properties.In this review,Bi-based photocatalysts(BiOX,BiVO_(4),Bi_(2)S_(3),Bi_(2)MoO_(6),and other Bi-based photocatalysts)have been summarized in the field of photocatalysis,including their applications of the removal of organic pollutants,hydrogen production,oxygen production etc.The preparation strategies on how to improve the photocatalytic performance and the possible photocatalytic mechanism are also summarized,which could supply new insights for fabricating high-efficient Bi-based photocatalysts.Finally,we summarize the current challenges and make a reasonable outlook on the future development direction of Bi-based photocatalysts.

Pinning energies of organic semiconductors in high-efficiency organic solar cells

With the emergence of new materials for high-efficiency organic solar cells(OSCs),understanding and finetuning the interface energetics become increasingly important.Precise determination of the so-called pinning energies,one of the critical characteristics of the material to predict the energy level alignment(ELA)at either electrode/organic or organic/organic interfaces,are urgently needed for the new materials.Here,pinning energies of a wide variety of newly developed donors and nonfullerene acceptors(NFAs)are measured through ultraviolet photoelectron spectroscopy.The positive pinning energies of the studied donors and the negative pinning energies of NFAs are in the same energy range of 4.3−4.6 eV,which follows the design rules developed for fullerene-based OSCs.The ELA for metal/organic and inorganic/organic interfaces follows the predicted behavior for all of the materials studied.For organic-organic heterojunctions where both the donor and the NFA feature strong intramolecular charge transfer,the pinning energies often underestimate the experimentally obtained interface vacuum level shift,which has consequences for OSC device performance.

Water electrolysis based on renewable energy for hydrogen production

As an energy storage medium,hydrogen has drawn the attention of research institutions and industry over the past decade,motivated in part by developments in renewable energy,which have led to unused surplus wind and photovoltaic power.Hydrogen production from water electrolysis is a good option to make full use of the surplus renewable energy.Among various technologies for producing hydrogen,water electrolysis using electricity from renewable power sources shows greatpromise.To investigate the prospects of water electrolysis for hydrogen production,this review compares different water electrolysis processes,i.e.,alkaline water electrolysis,proton exchange membrane water electrolysis,solid oxide water electrolysis,and alkaline anion exchange membrane water electrolysis.The ion transfer mechanisms,operating characteristics,energy consumption,and industrial products of different water electrolysis apparatus are introduced in this review.Prospects for new water electrolysis technologies are discussed.

Solar energy conversion on g-C3N4 photocatalyst:Light harvesting,charge separation,and surface kinetics

Photocatalysis. which utilizes solar energy to trigger chemical reactions, is one of the most desirable solar-energy-conversion approaches. Graphitic carbon nitride （g-C3N4）. as an attractive metal-free photocatalyst, has drawn worldwide research interest in the area of solar energy conversion due to its easy synthesis, earth-abundant nature, physicochemical stability and visible-light-responsive properties. Over the past ten years, g-C3N4 based photocatalysts have experienced intensive exploration, and great progress has been achieved. However, the solar conversion efficiency is still far from industrial applications due to the wide bandgap, severe charge recombination, and lack of surface active sites. Many strategies have been proposed to enhance the light absorption, reduce the recombination of charge carriers and accelerate the surface kinetics. This work makes a crucial review about the main contributions of various strategies to the light harvesting, charge separation and surface kinetics of g-C3N4 photocatalyst. Furthermore, the evaluation measurements for the enhanced light harvesting, reduced charge recombination and accelerated surface kinetics will be discussed. In addition, this review proposes future trends to enhance the photocatalytic performance of g-C3N4 photocatalyst for the solar energy conversion.

Latest progress in hydrogen production from solar water splitting via photocatalysis,photoelectrochemical,and photovoltaic-photoelectrochemical solutions

Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water splitting for hydrogen production in the past few years. This review summarizesthe very recent progress (mainly in the last 2–3 years) on three major types of solar hydrogenproduction systems: particulate photocatalysis (PC) systems, photoelectrochemical (PEC) systems,and photovoltaic‐photoelectrochemical (PV‐PEC) hybrid systems. The solar‐to‐hydrogen (STH)conversion efficiency of PC systems has recently exceeded 1.0% using a SrTiO3:La,Rh/Au/BiVO4:Mophotocatalyst, 2.5% for PEC water splitting on a tantalum nitride photoanode, and reached 22.4%for PV‐PEC water splitting using a multi‐junction GaInP/GaAs/Ge cell and Ni electrode hybrid system.The advantages and disadvantages of these systems for hydrogen production via solar watersplitting, especially for their potential demonstration and application in the future, are briefly describedand discussed. Finally, the challenges and opportunities for solar water splitting solutions are also forecasted.

Conversion of Solar Energy to Fuels by Inorganic Heterogeneous Systems

Over the last several years,the need to find clean and renewable energy sources has increased rapidly because current fossil fuels will not only eventually be depleted,but their continuous combustion leads to a dramatic increase in the carbon dioxide amount in atmosphere.Utilisation of the Sun's radiation can provide a solution to both problems.Hydrogen fuel can be generated by using solar energy to split water,and liquid fuels can be produced via direct CO2 photoreduction.This would create an essentially free carbon or at least carbon neutral energy cycle.In this tutorial review,the current progress in fuels' generation directly driven by solar energy is summarised.Fundamental mechanisms are discussed with suggestions for future research.

Solar Photocatalysis of A Pesticide in A Tubular Reactor on Titaniferous Sand as A New Semi-Conductor

This present study comes in addition to overcome the problems of separation of fine particles of TiO2 in heterogeneous photocatalysis after treatment. It aims to show the potential for using titaniferous sand as a new semiconductor under solar irradiation. The photocatalytic efficiency of this titaniferous sand was tested on a pesticide (Azadirachtin). A tubular photocatalytic reactor with recirculation of the polluting solution was designed for the elimination of the pesticide in an aqueous solution. Before its use as a photocatalyst, the titaniferous sand has undergone a specific treatment that consists of calcination at 600℃ followed by extraction of the calcined natural organic materials, which can interfere with the measurement of analytical parameters such as COD. The titaniferous sand was also characterized by X-ray fluorescence spectroscopy (XRF). XRF analyses have shown that TiO2 is predominant in the titaniferous sand with a percentage that has been estimated at 46.34%. The influence of various experimental parameters such as the flow rate of the polluting solution, the concentration of titaniferous sand, the presence of oxygen and the intensity of the overall rate of sunshine, was studied to optimize the photocatalytic degradation of the pesticide. The results showed that the highest removal rate (70%) was observed under the following conditions: a pH of 6, a titaniferous sand concentration of 150 g/L, a flow rate of 0.3 mL/min, and a sunshine rate of 354 W/m2 and in the presence of atmospheric oxygen. Under these experimental conditions, the rate of photodegradation of the pesticide follows the pseudo first order kinetic model of Langmuir Hinshelwood with a coefficient of determination R2 of 0.9869 and an apparent rate constant of 0.0029 min-1. The results clearly demonstrated the potential of titaniferous sand as a photocatalyst sensitive to sunlight for the effective removal of pesticides in the aquatic environment.

Photoconductive Effect of Liquid and Utilization of Solar Energy

Experiments described in this paper show that there is the photoconductive effect of liquid, i.e. when light shines into a sort of alkali, acid or salt solution, the conductivity of the solution will increase. The mechanism of the effect is explained as follows. When hydrated ions in the solution absorb photons with their high enough energies, they will decompose to naked ions and water-molecules. The naked ions can reach an anode or a cathode more easily and faster than the hydrated ions;It is possible that when a molecule in the solution absorbs a photon with its high enough energy, it will decompose to negative and positive ions. Based on the effect, a device producing hydrogen by the solar-energy had been devised.

Feasibility Study for a Solar-Energy Stand-Alone System: (S.E.S.A.S.)

The present study is aimed to serve a small community living on Stand-Alone Solar-Energy (S.A.S.E.S) system. As a basis for the study 1 cubic meter of hydrogen is to be produced by electrolysis in 5 hrs that requires energy input of 5 KW-hr. The proposed system consists of the following main components: photovoltaic module, water electrolyzer and fuel cell. Solar hydrogen production by water electrolysis is described and design parameters are specified. Economic feasibility of the proposed system is evaluated. The projected cost of hydrogen is calculated and found to be 5 cents/ft3.

Methanol from CO2 and Solar Energy A Literature Review

The project ＂SolMethCO2＂ deals with the options of an effective methanol synthesis from atmospheric or industrial CO2 sources by implementing solar energy. First part of the projects is a wide-range survey of the many different processes and sub-processes that may be involved in methanol production and of the possibilities how to make these processes available for solarization. The different fields of research were CO2 capturing, Hg/syngas-synthesis, biotechnological techniques for methanol synthesis, photocatalytical approaches and solar reactor.

Recent Progress and Approaches on Carbon-Free Energy from Water Splitting

Sunlight is the most abundant renewable energy resource,providing the earth with enough power that is capable of taking care of all of humanity’s desires-a hundred times over.However,as it is at times diffuse and intermittent,it raises issues concerning how best to reap this energy and store it for times when the Sun is not shining.With increasing population in the world and modern economic development,there will be an additional increase in energy demand.Devices that use daylight to separate water into individual chemical elements may well be the answer to this issue,as water splitting produces an ideal fuel.If such devices that generate fuel were to become widely adopted,they must be low in cost,both for supplying and operation.Therefore,it is essential to research for cheap technologies for water ripping.This review summarizes the progress made toward such development,the open challenges existing,and the approaches undertaken to generate carbon-free energy through water splitting.

光催化制备过氧化氢的研究进展

过氧化氢是一种高价值、多功能的绿色化学品,被广泛应用于各种工业生产以及清洁能源燃料等领域。传统蒽醌法制备过氧化氢的工艺不仅能耗巨大,且会产生各种化学废料,环境污染较大。光催化技术是近年来生产H_(2)O_(2)的一种绿色环保和发展前景广阔的新方法,但其仍受制于光催化活性较低、H_(2)O_(2)产量较低和反应较慢等问题。简要阐述了光催化制备H_(2)O_(2)基本原理,介绍了光催化制备H_(2)O_(2)的研究进展,对比分析了不同光催化材料的结构及光催化性能,归纳总结了光催化材料的结构调控及性能提高途径和策略,提出了存在的问题,并展望了未来的发展方向。

光解水制氢催化剂的掺杂改性

光催化分解水制氢,作为一种绿色、安全、高效且低成本的制氢技术,因其清洁性和巨大的发展潜力而受到广泛关注.尽管光催化分解水制氢在理论上具有显著优势,但在实际应用中仍面临捕光效率低、电荷分离难、表面反应速率慢以及光腐蚀等挑战.为解决上述问题并突破效率瓶颈,研究者们积极探索新的方法,如构建异质结、调控微观结构、引入助催化剂、掺杂和诱导缺陷等,以期提高光催化剂的性能.其中,光催化剂掺杂改性是研究热点之一.通过对光催化剂进行掺杂改性,可以有效调节其能带结构、光吸收性能以及电荷传输性能,进而提升光催化分解水制氢的效率.因此,对光催化剂掺杂在光催化分解水制氢中的作用机制和研究进展进行系统地梳理和总结,有助于深化对该领域的理解,具有重要意义.本文系统地介绍了近年来本课题组利用掺杂改性光催化剂提升光解水制氢性能的研究成果.首先,总结了光催化剂掺杂的合成方法和表征手段,并详细介绍了用于分析掺杂离子在催化剂中的分布及价态的原位表征方法.其次,以铋基复合氧化物为例,介绍了通过固溶法将稀土元素掺杂到铋基复合氧化物中,实现可见光下完全分解水,并探讨了掺杂对光催化剂能带结构的影响及作用机制.进一步,阐述了掺杂后铋基复合氧化物微观结构的变化,特别是暴露面、表面特性和缺陷态等对光生载流子分离与迁移的影响,归纳了掺杂诱导的结构变化与光催化分解水制氢性能之间的构效关系.此外,介绍了一种新颖的多局域梯度掺杂方法:利用离子扩散使预先储存掺杂离子的“纳米胶囊”持续、非均匀地释放入半导体材料中,诱导导带位置连续弯曲,从而在导带势能面内构建出多局域的势阱,从而延长了光生电子空穴对的寿命,为光生载流子提供了更多迁移至表面的通道,明显提高了光解水效率.最后,展望了光催化剂掺杂技术未来的研究方向:(1)通过对光催化分解水制氢中的析氢和析氧助催化剂进行掺杂改性,提高表面催化反应速率;(2)发展纳米催化剂上的非对称掺杂技术,在纳米颗粒内的特定区域或表面掺杂的精确调控,以提高光催化分解水制氢性能;(3)随着机器学习的进步,AI模型可以用于预测和优化掺杂条件,从而大幅减少实验量.综上,本文总结了掺杂在光催化分解水制氢研究中的研究进展,希望能为探索开发可见光光催化水分解的新型材料和提高能量转换效率提供参考和借鉴.