Solar Energy Water Research Articles

Site Suitability Analysis for Green Hydrogen Production Using Multi-Criteria Decision-Making Methods: A Case Study in The State of Ceará, Brazil

– Brazil is leveraging its extensive potential in solar, wind, and hydro energy to establish itself on the global map of green hydrogen production—a pivotal component in the ongoing energy transition. The economic viability of green hydrogen hinges on optimal locations with abundant renewable resources, space for solar or wind farms, access to water, and the potential for exporting to major demand centers. In this context, this study evaluates the potential for green hydrogen production in the State of Ceará, Brazil, using multi-criteria decision-making (MCDM) methods, which are designed to prioritize conflicting tangible and intangible criteria to determine the best decision alternatives. The additive ratio assessment (ARAS), simple additive weighting (SAW), combinative distance-based assessment (CODAS), and technique for order performance by similarity to ideal solution (TOPSIS) methods are evaluated for decision-making purposes, with weighting and aggregation relying on the best-worst method (BWM) and ensemble ranking. Criteria considered in the analysis include suitable areas for wind and solar farms, wind and solar energy potentials, water availability, surface temperature, electrical infrastructure, population, and local gross domestic product (GDP). The municipalities with the highest potential for renewable hydrogen production identified are Tauá (638 kton/year), Araripe (471 kton/year), and Beberibe (462 kton/year). According to the results, Araripe emerges as the most suitable municipality for green hydrogen production in Ceará.

A Bio-Inspired Magnetic Soft Robotic Fish for Efficient Solar-Energy Driven Water Purification.

Solar-driven water evaporation is a promising solution for global water scarcity but is still facing challenges due to its substantial energy requirements. Here, a magnetic soft robotic bionic fish is developed by combining magnetic nanoparticles (Fe3O4), poly(N-isopropylacrylamide), and carboxymethyl chitosan. This bionic fish can release liquid water through hydrophilic/hydrophobic phase transition and dramatically reduce energy consumption. The introduced Fe3O4 nanoparticles endow the bionic fish with magnetic actuation capability, allowing for remote operation and recovery. Additionally, the magnetic actuation process accelerates the water absorption rate of the bionic fish as confirmed by the finite element simulations. The results demonstrate that bionic fish can effectively remove not only organic molecular dyes dissolved in water but also harmful microbes and insoluble microparticles from natural lakes. Moreover, the bionic fish maintains a good purification efficiency even after five recycling cycles. Furthermore, the bionic fish possesses other functions, such as salt purification and salt rejection. Finally, the mechanism of water purification is explained in conjunction with molecular dynamics calculations. This work provides a new approach for efficient solar-energy water purification by phase transition behavior in soft robotics.

Modification of solar energy and photoelectrochemical water splitting properties: using FTO/Er-TiO2/MAPbI3/CuPc/Au as modified photoelectrode

In the past decades, converting solar energy into hydrogen through photoelectrochemical water splitting has been attracted. Here, we designed a new FTO/Er-TiO2/MAPbI3/CuPc/Au photoanode with n-i-p structure for using in solar water splitting. Accourding to obtained PEC results, the FTO/Er-TiO2/MAPbI3/CuPc/Au photoanode has a photocurrent density of ∼9.8 mA cm−2 ( under a visible lamp with intensity of 100 mW cm−2 irradiation) compared to FTO/Er-TiO2/Au and FTO/Er-TiO2/MAPbI3/Au photoanodes with photocurrent density of 0.7 and 6.12 mA cm−2, respectively. This important enhancement is refered to the light absorption feature of Er-TiO2/MAPbI3 and a fast electron and hole transfer process in the Er-TiO2 and CuPc, respectively. The photoelectrochemical action of the photoelectrode is increased using erbium doping due to creation of oxygen vacancies and titanium (III) ions. Furthermore, in this research, we studided the power conversion efficiency (PCE) of FTO/Er-TiO2/MAPbI3/Au and FTO/Er-TiO2/MAPbI3/CuPc/Au solar cells. The results shown that the significant enhancement in photovoltaic properties can be observed by utilizing spin-coated CuPc nanoparticles (as hole transport layer) at least by 1.39% compared to the FTO/Er-TiO2/MAPbI3 perovskite solar cell.

A Preliminary Study of Context Integration as A Determinant in The Effectiveness of Digital Mathematics Games

Contexts in the digital learning environment are one of the crucial components regarding students’ motivation and positive attitude development toward content. Although there is not enough guiding information in the literature about how contexts should be, previous research has shown that even digital game contexts are effective in developing students’ environmental awareness. To reveal the impact of contexts in the digital learning environment, it is necessary to consider the variables regarding the socio-economic and cultural status of the students. Therefore, it can be envisaged that the effect of digital game contexts may differ depending on students’ experiences and social environments. For this purpose, digital games were designed in two different contexts in this research. In these digital games, two opposite contexts were selected. The first context was focused on saving nature and green energy. This context includes different levels of digital games on topics such as solar energy, reforestation, and clean water sources. The second context was focused on unregulated industrial development that negatively affects nature by ignoring it. This context includes different levels of digital games such as building thermal power plants, building chemical factories, and turning forests into fields. Apart from the contexts, the other variables in both games (i.e., gameplay, artistic structure, levels of problem parameters) are the same. At each game level, students were asked to solve mathematical problems regarding ratio-proportion. In this study, the preliminary findings, which were derived from a large experimental study, were presented. The participants of this study were 15 gifted eighth-grade students from Turkey. Among the participants, eight students played the digital game regarding the context of green energy, and the remaining seven students played the digital game regarding the context of unregulated industrial development. Preliminary findings showed that students were more interested in the digital game regarding the context of unregulated industrial development as it included interesting and beneficial topics such as energy generation and economic development. The resident perception of the citizens regarding the acute need for energy generation and economic development rather than saving nature and green energy since Turkey represents a developing country may explain this finding.

Thermodynamic analysis of a solar-driven supercritical water gasification-oxidation system for ammonia production and heat supply from chicken manure

Faced with the dual challenges of energy shortage and environmental pollution, researchers are turning to extracting clean energy from waste resources. The coupled system of solar energy and supercritical water gasification offers a novel solution to these issues. In this study, a solar-driven supercritical water gasification-oxidation system for ammonia production and heat supply from chicken manure was simulated. Additionally, the effects of temperature of supercritical water gasification, chicken manure slurry concentration, water-dry matter ratio, and pressure of supercritical water gasification and oxidation on the system's products, efficiency, and device exergy losses were examined. Under typical working conditions (the temperature of supercritical water gasification: 750 °C, chicken manure slurry concentration: 50 wt%, water-dry matter ratio: 5, the pressure of supercritical water gasification and oxidation: 25 MPa), and the system had a treatment capacity of 5 t/h of dry chicken manure. The system yielded 2604.04 kg/h of NH3 and 23763.9 kg/h of heating steam. It demonstrated an energy efficiency of 68.38% and an exergy efficiency of 46.85%. The total exergy losses of the system amounted to 34704.73kw, with the solar collector accounting for the largest share at 49.6%. The temperature of supercritical water gasification and water-dry matter ratio significantly impacted the system efficiency. Conversely, chicken manure slurry concentration and the pressure of supercritical water gasification and oxidation exerted minimal influence. The solar collector and gasification reactor emerged as the primary contributors to exergy losses in the entire system. Notably, the lower temperatures of supercritical water gasification, chicken manure slurry concentrations, pressures of supercritical water gasification and oxidation, and water-dry matter ratios can reduce exergy losses in both the solar collector and the gasification reactor.

Vertically aligned aerogel with concaved surface topography coupled ordered channel enable efficient solar-driven desalination

Solar-driven desalination has been regarded as a promising energy-saving and sustainable strategy to address the serious freshwater shortage issue. However, its performance is restricted by low solar energy utilization efficiency, water transport, and serious salt deposition. Herein, an efficient solar-driven interfacial evaporator with high solar energy utilization efficiency, fast water transport and robust salt tolerance was developed, via constructing vertically aligned sodium alginate (SA) aerogel with concave surface topography coupled ordered water transport channel structure. Concaved reflecting valley surface was assembled with 3D hierarchical photothermal networks of 2D MXene synergistic 1D carbon nanotube to enhance light absorption capacity. Concaved surface topography with multiple reflective nanostructure (angle 45°, depth 1.5 cm) owns strong sunlight concentration performance, which effectively avoid the light loss and thus enhance the light-absorption over a broad spectrum (0.3–2.5 μm). In another way, hydrophilic SA aerogel with vertically aligned structure, which also provides ordered channels for fast water/vapor transport and high salt rejection ability via strong wicking and diffusion effect. Solar-driven interfacial evaporator with such unique concaved surface topography that coupled ordered valley channels exhibits excellent evaporation rate (2.81kg m−2h−1) and remarkable solar energy utilizing efficiency (98.52 %), while with excellent antibacterial ability during continuously desalination process. Solar-driven interfacial evaporator with unique concaved surface topography coupled ordered valley channels holds great potential in sustainable water purification and desalination.

The effect of adding layers of date stones on the profitability of brackish water solar desalination process

Lately, there has been a pronounced and alarming up tick in the global demand for fresh water, resulting in a limited availability of this precious resource. Solar desalination emerges as a promising solution, particularly for supplying the sparsely populated desert regions in the southern regions of Algeria, where plentiful solar energy and subterranean brackish water resources are present.The current paper seeks to optimize the performance of traditional solar stills and elevate the quality of distilled water by incorporating layers of blackened date stones as an additional heat storage medium. Date stones, typically discarded post-date consumption, undergo a process of washing and blackening before being introduced in two forms (stone and powder). They are then uniformly distributed across the horizontal surface of solar still’s absorber.Three solar stills of identical design featuring glass sides were designed, manufactured, and subjected to testing to compare their productivity with that of a control unit. Experimental trials conducted at Ouargla University reveal significant enhancements the inclusion of a single layer of date stones (approximately 2.210 kg/ (m2 of absorber area)) leads to a remarkable 45.66 % increase in yield. Conversely, an equivalent amount (≈ 504 g) of date stones in powder form results in a 29.42 % improvement in yield. Notably, the distillate quality is substantially enhanced in both cases contrasted with the conventional setup.

Tortuosity Engineering of Water Channels to Customized Water Supply for Enhancing Hydrogel Solar Evaporation.

Hydrogel as a solar evaporator shows great potential in freshwater production. However, hydrogels often lead to an imbalance between solar energy input and water supply management due to their excessively high saturated water content. Thus, achieving a stable water-energy-balance in hydrogel evaporators remains challenging. Here, by tortuosity engineering designed water transport channels, a seamless high-tortuosity/low-tortuosity/high-tortuosity structured hydrogel (SHLH structure hydrogel) evaporator is developed, which enables the hydrogel with customized water transport rate, leading to the controlled water supply at the evaporator interface. An excellent equilibrium between the photothermal conversion and water supply is established, and the maximum utilization of solar energy is realized, thereby achieving an excellent evaporation rate of 3.64kg m-2h-1 under one solar illumination. This tortuosity engineering controlled SHLH structured evaporator provides a novel strategy to attain water-energy-balance and expands new approaches for constructing hydrogel-based evaporators with tailored water transportation capacity.

Ginseng‐Bioinspired 3D Photothermal Evaporator for Efficient Seawater Desalination Using Conjugated Microporous Polymer

AbstractPhotothermal conversion technology presents a promising approach for harnessing solar energy to facilitate seawater desalination. However, salts will accumulate on the surface of the photothermal conversion structure during seawater desalination, which hinders solar energy absorption. Meanwhile, the photothermal conversion structure directly immersing in a large water body results in a large heat dissipation loss. Both factors impair solar energy conversion and water steam generation. To address the issues, inspired by a ginseng plant (with a trunk‐to‐branch water supply system), a 3D cotton‐based photothermal evaporator with tunable water supply is facilely designed herein via simple cloak‐weaving of a porphyrin‐based conjugated microporous polymer (PPCMP) as the photothermal conversion material. The as‐designed 3D cloak‐like photothermal evaporator achieves an equilibrium between the water supply flux and evaporation rate via optimizing PPCMP weaving and the water path. As a result, a high evaporation rate of 2.81 kg m−2 h−1 and photothermal conversion efficiency of 155% are obtained under 1 sun illumination. The findings underline the importance of 3D porous organic polymer‐based fabrics as effective media for harnessing solar energy and highlight their potential for seawater desalination.

Controlled synthesis of SnSxSe2-x thin films for solar energy water splitting

Earth-abundant and ecofriendly minerals SnSxSe2–x can be promising candidates for photoelectrochemical (PEC) cells because of their tunable band gaps and high absorption efficiency in the visible light range. In this paper, p type SnS thin films with sheet-like morphologies were successfully prepared by CBD method and then n-type SnSxSe2-x thin films were achieved by selenization annealing of SnS thin films. The physical properties and PEC performances of SnSxSe2-x thin films influenced by the annealing process were detailed studied. The photocurrent densities and stability of SnSxSe2-x films were further improved by the deposition of p-type CdS:Cu buffer layer. And the fabrication of FTO/SnSxSe2-x/CdS:Cu/TiO2/Pt photocathode improved the PEC performance further and the photocurrent as high as 10.5 mA/cm2 had been achieved. IPCE tests indicated that the FTO/SnSxSe2-x/CdS:Cu/TiO2/Pt structure achieved a power conversion efficiency of 31.3 %.

A General Group-Protection Synthesis Strategy to Fabricate Covalent Organic Framework Gels.

Fabricating insoluble and infusible porous materials into gels for advanced applications is of great importance but has formidable challenges. Here, we present a general, facile, and scalable protocol to fabricate covalent organic framework (COF) gels using a group-protection synthesis strategy. To prove the generality of this strategy, we successfully prepared 10 types of COF organohydrogels with high crystallinity, porosity, good mechanical properties, and excellent solvent and freezing resistance. Notably, these COF organohydrogels can easily transform into hydrogels, organogels, and aerogels, breaking the gaps between different types of COF gels. An in-depth mechanism investigation unveils that the group-protection strategy effectively slows down the formation rate and regulates the morphology of COFs, benefiting the formation of cross-linked nanofibers/nanosheets to produce COF gels. We also find that the hydrogen bond network formed by the organic/water binary solvent and functional groups in the COF skeletons plays a vital role in creating organohydrogels and maintaining frost resistance and solvent resistance. As an application demonstration, COF gels installed with photoresponsive azobenzene groups show excellent solar energy absorption, photothermal conversion, and water transmission performances, demonstrating great potential in solar desalination. This work enriches the synthesis toolboxes for COF gels and expands the application scope of COFs.

Theoretical Evaluation of Photovoltaic Thermal Water Source Heat Pump, Application Potential and Policy Implications: Evidence from Yangtze River Economic Belt, China

In the context of carbon neutrality, making full use of renewable energy is the key to further improve China’s development index. Within China’s Yangtze River Economic Belt, solar energy and river water, as clean and abundant sources of renewable energy, have garnered increasing. In this paper, a solar energy and surface water driven cogeneration system model is developed by TRNSYS to provide users with heat, cold and electricity. Six representative cities located along the upper, middle, and lower reaches of the Yangtze River Economic Belt were selected to evaluate and analyze the energy-saving, emission reducing, and economic and environmental benefits of solar energy and river water heat utilization in the aspects of energy, economy, and environment. The results shows that the annual power output of PV/T-GSHP system, from the west to the east of the Yangtze River, shows a phase growth trend, which is related to the light intensity. The annual heat output of PV/T plate gradually decreases from the lower reaches of the Yangtze River to the upper reaches. The research findings confirm the application potential of new energy sources in the Yangtze River Economic Belt and quantify the emission reduction effects of new environmental protection actions such as solar energy and river water heat sources. It provides valuable guidance for the utilization of new energy sources, including solar energy and surface water heat energy in the Yangtze River Economic Belt, as well as for optimizing energy policies.

Novel concepts and engineering strategies for heterologous expression of efficient hydrogenases in photosynthetic microorganisms.

Hydrogen is considered one of the key enablers of the transition towards a sustainable and net-zero carbon economy. When produced from renewable sources, hydrogen can be used as a clean and carbon-free energy carrier, as well as improve the sustainability of a wide range of industrial processes. Photobiological hydrogen production is considered one of the most promising technologies, avoiding the need for renewable electricity and rare earth metal elements, the demands for which are greatly increasing due to the current simultaneous electrification and decarbonization goals. Photobiological hydrogen production employs photosynthetic microorganisms to harvest solar energy and split water into molecular oxygen and hydrogen gas, unlocking the long-pursued target of solar energy storage. However, photobiological hydrogen production has to-date been constrained by several limitations. This review aims to discuss the current state-of-the art regarding hydrogenase-driven photobiological hydrogen production. Emphasis is placed on engineering strategies for the expression of improved, non-native, hydrogenases or photosynthesis re-engineering, as well as their combination as one of the most promising pathways to develop viable large-scale hydrogen green cell factories. Herein we provide an overview of the current knowledge and technological gaps curbing the development of photobiological hydrogenase-driven hydrogen production, as well as summarizing the recent advances and future prospects regarding the expression of non-native hydrogenases in cyanobacteria and green algae with an emphasis on [FeFe] hydrogenases.

SACTI model in prediction and assessment of large scale natural draft cooling tower environmental impact of nuclear power plant

Large Scale Natural Draft Cooling Tower has become a hot topic in China because it is an important part of the nuclear power plant, and its environmental impacts include shading, solar energy loss, water deposition and salt deposition. In China, there is no built large-scale natural draft cooling tower of nuclear power plant. Therefore, model prediction becomes an effective way to solve this problem. This paper introduces the basic principles and structure of SACTI (Seasonal and Annual Cooling Tower Impact) model. SACTI is a cooling tower assessment model developed by Argonne National Laboratory, USA. A comparative case study between China's Pengze Nuclear Power Plant and the US Amos Power Plant is also presented. Calculations were carried out for the Pengze and Amos power plants, and the results showed that the maximum value of salt deposition at the Pengze plant was about 166.5 kg/(km2-month) at a distance of 800 m from the cooling tower. The maximum value of salt deposition at the Amos plant was about 92.85 kg/(km2-month) at a distance of 600 m from the cooling tower. Conclusions show that the research work can provide a useful solution in future work, the simulation results of the SACTI model have a potential mean in the absence of monitoring data. This research provides a way to generate simulation data through SACTI program in the design process of nuclear power plant cooling tower, and designers can use these data to determine how the cooling tower will affect the natural environment and manage within an appropriate range to reduce the impact on the environment.

EFISIENSI TERMAL DESAIN SISTEM PEMANAS AIR ENERGI MATAHARI DENGAN VARIASI JUMLAH PIPA BESI

This study aims to determine the average value of hot water temperature and thermal efficiency that can be produced by using iron pipes as fluid collectors in the Solar Energy Water Heater design system. Collector pipes are made in three variations of 5, 7 and 9 pipes which are placed in a wooden box with transparent glass as a cover on the collector surface. The inside of the wooden box is lined with styrofoam and aluminum foil to reduce heat loss to the environment. Data were collected by observing and measuring the temperature of hot water with three variations of the number of pipes, each variation of the number of pipes carried out for three days. This water temperature measurement was carried out for 6 hours, from 10.20-16.30 WIT. The average maximum temperature produced for a total of 5 collector pipes is 59.70C, a total of 7 pipes is 63.70C, and a total of 9 collector pipes is 61.70C. The thermal efficiency value of the solar energy water heating system design for the number of 5 collector pipes is 96% , the number of 7 collector pipes is 97%, and the 9 collector pipes is 99%.

CdS supported on ZIF-67-derived Co-N-C as efficient nano polyhedron photocatalysts for visible light induced hydrogen production

Hydrogen energy is vital important for solving pollution of environment and energy shortage. Hydrogen production via solar energy and semiconductor photo-splitting water is one of the most environmentally friendly strategies at present. In this work, Co-N-C, a non-noble metal-based ZIF-67 derivative, was employed as a co-catalyst to achieve an in situ growth of spherical CdS via simple one-step hydrothermal. Due to the large specific surface area of Co-N-C, the agglomeration of CdS is avoided and the photocorrosion phenomenon is weakened. Under irradiation of visible light, the hydrogen generation activity of Co-N-C/CdS was achieved 905 μmol g−1 h−1. It is 6 times that of pure CdS with excellent stability. At the contact interface of the Co-N-C and CdS, the transfer and the separation of photoinduced carriers had been enhanced by a great many of channels. DFT calculation further showed that Co nanoclusters, as the active sites of hydrogen production, significantly enhanced photocatalytic hydrogen evolution activity. Therefore, Co-N-C not only acts as electron acceptor, but also serves as support of highly dispersed CdS to promote the stability of system during photocatalytic hydrogen generation. This work demonstrates the advantages of CdS binding MOF derivatives to construct composite photocatalysts with enhanced dispersibility and hydrogen production activity.

Hierarchical porous metallic glass with strong broadband absorption and photothermal conversion performance for solar steam generation

The development of a strong light absorption absorber with a facile preparation process are crucial for some photothermal conversion applications, such as solar steam generation, photothermal catalysis and detectors. Here, a hierarchical structure based on microporous surface equipped with nanoporous layer is ingeniously designed and fabricated benefiting from the unique thermoplastic forming ability of metallic glasses by using the soluble clusters as template in less than 30 s. The presence of hierarchical porous structures induces multiple reflection of light and excites the plasmonic behavior of surface, achieving over 90% light absorption in the 380–20 µm wavelength range and the broad light incident angle from 0° to 70°, resulting in a remarkable photothermal conversion performance. Compared to conventional and existing absorber, the innovatively designed and fabricated metallic surface offers outstanding advantages in terms of light absorption range, heating rate and maximum temperature rise. Afterwards, the hierarchical porous structures for solar steam generation shows an evaporation efficiency of up to 94.2% and evaporation rate of 1.72 kg m−2 h−1 at 1 kW m−2. The design of unprecedented structure on metallic glass opens up a new strategy for solar energy harvesting, water treatment and other related fields.

TiO2/Au/TiO2 Plasmonic Photocatalysts: The Influence of Titania Matrix and Gold Properties

Plasmonic photocatalysts have gained more and more attention because of possible applications for solar energy conversion, environmental decontamination, and water treatment. However, the activity under visible light is usually very low, and the property-governed activity as well as the mechanisms are not fully understood yet. Accordingly, this study examines four different titania photocatalysts (anatase and rutile with fine and large crystallites) modified with gold by photodeposition. Three kinds of samples were prepared, as follows: (i) gold-modified titania (Au/TiO2), (ii) physically mixed Au/TiO2 samples (Au/TiO2(1) + Au/TiO2(2)), and (iii) Au/(TiO2(1) + Au/TiO2(2)) samples, prepared by subsequent deposition of gold on the mixture of bare and gold-modified titania. In total, twelve samples were prepared and well characterized, including diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM). The photocatalytic activity was examined in three reaction systems: (i) methanol dehydrogenation during gold photodeposition under UV/vis irradiation, (ii) oxidative decomposition of acetic acid (UV/vis), and (iii) oxidation of 2-propanol to acetone under visible light irradiation (λ > 450 nm). It was found that during subsequent deposition, gold is mainly formed on the surface of pre-deposited Au nanoparticles (NPs), localized on fine titania NPs, through the electrostatic attractions (negatively charged gold resulting from photogenerated electrons’ accumulation). This gold aggregation, though detrimental for UV activity (many “naked” large titania with low activity), is highly beneficial for vis activity because of efficient light harvesting and increased interface between gold and titania (gold deposits surrounded by fine titania NPs). Moreover, it was found that rutile is more active than anatase for plasmonic photocatalysis, probably due to easier electron transfer from gold via titania to adsorbed oxygen (more negative conduction band), which might hinder the back reaction (electron transfer: Au→TiO2→Au).

Geospatial Approaches to Model Renewable Energy Requirements of the New Capital City of Indonesia

Predicting how a planned city will develop and expand after its construction, and which resources, such as energy, the city will need over time is only possible if one can rely on similar examples and reliable models. Given the existing spatial plans for the design of the new capital city of Indonesia, there is a need to develop and compare city development scenarios–in spatial expansion, population size, resource, energy and food requirements. A combination of various geospatial data approaches can address this knowledge and assessment gap. This article investigates spatial expansion, forest encroachment and sustainable energy infrastructure requirements using open access geodata and models. The hypothesis is that the constitution of the new capital city of Indonesia can rely on existing energy infrastructures but may also need to rely on additional resources. The research approach was to collect and integrate different types of geospatial data related to land use, terrain characteristics and population growth assumptions and connect these to both urban growth models and predictions and energy. This relied on land use change methodologies and urban growth models to simulate and predict spatial effects, with ca particular focus on the expansion of energy requirements. The choice to focus on energy requirements additionally required a comparison of different kinds of energy sources, such as solar and wind energy. The conclusion is that all design and expansion scenarios indicate a possible spatial conflict between locating sustainable energy production facilities with maintaining ecologically sensitive areas. A possible solution is to make use of existing mining infrastructures to enhance sustainable energy production and to make use of dual land and water solar energy systems.

Resin with short-range π-π stacking aggregates for an efficient photocatalyst

A short-range π-π stacking aggregate photocatalyst (TE-resin) was facilely prepared by covalent grafting TE molecules onto crosslinked polystyrene-based macroporous resin, which displays short charge migration distance and efficient separation of electrons and holes, improved light absorption range and wettability , so TE-resin exhibits excellent photocatalytic activity and stability. • Short range π-π stacking aggregates were constructed by resin as a support. • Short-range π-π stacking aggregates display improved photocatalytic activity. • Short-range π-π stacking aggregates reduce the charge recombination efficiency. • Aggregate has good stability due to covalent bond connection between it and resin. Self-assembled supramolecular photocatalysts have aroused intensive attraction in extensive fields of solar energy conversion, water splitting and energy storage. However, the photocatalysts constructed by long range π-π stacking interaction usually display low photocatalytic activity because the holes and electrons recombine easily as they migrate along the long range π-π stacking structure. To overcome their shortcoming, for the first time, short-range π-π stacking aggregates were facilely prepared by covalent grafting 4′-(pethanediamine phenyl)-2,2′:6′,2″-terpyridine (TE) onto crosslinked polystyrene macroporous resin to form an efficient and stable photocatalyst. In the grafted resin, TE molecules linked to the resin molecules form a monolayer structure by short-range π-π stacking interaction along the polymer chains, which not only shortens the charge migration distance and reduces the charge recombination efficiency, but also efficiently improves light absorption range and wettability of the as-prepared photocatalyst. The above advantages endow the as-prepared photocatalyst with an excellent photocatalytic performance, for example, it affords a hydrogen evolution rate of 227.5 umol g -1 h −1 under UV–vis irradiation. Moreover, the covalent bond connection between TE aggregates and resin improves the stability of TE aggregates, enhancing their recycling. Overall, our work provides a convenient route for the preparation of efficient and stable short-range π-π aggregate photocatalyst assisted by resin for environmental and energetic applications.