Synthesis Of Advanced Materials Research Articles

Biomass-Derived Carbon Materials for Advanced Metal-Ion Hybrid Supercapacitors: A Step Towards More Sustainable Energy

Modern research has made the search for high-performance, sustainable, and efficient energy storage technologies a main focus, especially in light of the growing environmental and energy-demanding issues. This review paper focuses on the pivotal role of biomass-derived carbon (BDC) materials in the development of high-performance metal-ion hybrid supercapacitors (MIHSCs), specifically targeting sodium (Na)-, potassium (K)-, aluminium (Al)-, and zinc (Zn)-ion-based systems. Due to their widespread availability, renewable nature, and exceptional physicochemical properties, BDC materials are ideal for supercapacitor electrodes, which perfectly balance environmental sustainability and technological advancement. This paper delves into the synthesis, functionalization, and structural engineering of advanced biomass-based carbon materials, highlighting the strategies to enhance their electrochemical performance. It elaborates on the unique characteristics of these carbons, such as high specific surface area, tuneable porosity, and heteroatom doping, which are pivotal in achieving superior capacitance, energy density, and cycling stability in Na-, K-, Al-, and Zn-ion hybrid supercapacitors. Furthermore, the compatibility of BDCs with metal-ion electrolytes and their role in facilitating ion transport and charge storage mechanisms are critically analysed. Novelty arises from a comprehensive comparison of these carbon materials across metal-ion systems, unveiling the synergistic effects of BDCs’ structural attributes on the performance of each supercapacitor type. This review also casts light on the current challenges, such as scalability, cost-effectiveness, and performance consistency, offering insightful perspectives for future research. This review underscores the transformative potential of BDC materials in MIHSCs and paves the way for next-generation energy storage technologies that are both high-performing and ecologically friendly. It calls for continued innovation and interdisciplinary collaboration to explore these sustainable materials, thereby contributing to advancing green energy technologies.

Stability, Chemical Bonding, and Electron Lone Pair Localization in AsN at High Pressure by Density Functional Theory Calculations.

The covalent bonding framework of crystalline single-bonded cubic AsN, recently synthesized under high pressure and high temperature conditions in a laser-heated diamond anvil cell, is here studied by means of density functional theory calculations and compared to single crystal X-ray diffraction data. The precise localization of the nonbonding electron lone pairs and the determination of their distances and orientations are related to the presence of characteristic structural motifs and space regions of the unit cell dominated by repulsive electronic interactions, with the relative orientation of the electron lone pairs playing a key role in minimizing the energy of the structure. We find that the vibrational modes associated with the expression of the lone pairs are strongly localized, an observation that may have implications for the thermal conductivity of the compound. The results indicate the thermodynamic stability of the experimentally observed structure of AsN above ∼17 GPa, provide a detailed insight into the nature of the chemical bonding network underlying the formation of this compound, and open new perspectives to the design and high pressure synthesis of new pnictogen-based advanced materials for potential applications of energetic and technological relevance.

Mechanochemistry: A Green and Fast Method to Prepare a New Generation of Metal Supported Catalysts

In this review, we report on recent advances in the use of mechanochemistry to synthesise new catalytic materials. We report recent results obtained by our groups where a rational design of the milling parameters led to the synthesis of advanced materials with novel properties such as unconventional arrangements of metals on the surface of oxide support materials, highly dispersed metals or the stabilisation of species in particular oxidation states. These properties resulted in superior catalytic performances of the mechanochemically-synthesised catalysts compared to their counterparts prepared by traditional impregnation methods. To illustrate these advances, we review the progress made in two important fields of catalysis where noble metals are used: (i) emission control catalysis using palladium-based materials; (ii) the development of photocatalysts to produce hydrogen based on gold and palladium materials.

Low‐Carbon‐Footprint Plasma‐Functionalized Coconut‐Coir‐Based Porous Carbon as an Efficient and Sustainable Adsorbent

AbstractHerein, the surface of pyrolyzed coconut coir (PCC) dust has been functionalized using atmospheric plasma under non‐equilibrium conditions without utilizing vacuum chambers. The reactive species present in the plasma such as, molecular ions, electrons, and radicals interact with PCC's surface, leading to the introduction of epoxy, carbonyl and amino functional groups on carbon surface. The resulting plasma functionalized carbon (PFC) material was characterized using several advanced material characterization techniques, including PXRD, FTIR, XPS, N2 BET specific surface area, SEM and TEM imaging techniques, etc. Moreover, it has been used in diverse applications in toxic gas removal (CO2, CO, NOx), fluoride (F−) removal from drinking water and cationic organic dye (methylene blue–MB) removal. The reported method for synthesis of functional carbon introduces a platform technology for low carbon footprint, green synthesis of advanced functional materials.

Controlled synthesis of Cadmium doped CuBi2O4 nanorods with rapid and synergistic visible light photocatalytic performance

The rise of nanotechnology has significantly influenced the synthesis of advanced photo materials and their various potential applications. In this study, newly advanced multicomponent photocatalyst was designed by a simple hydrothermal method i.e., CuBi2O4, Cd0.05Cu0.95Bi2O4, Cd0.1Cu0.90Bi2O4, and Cd0.15Cu0.85Bi2O4. These nanostructures were characterized using various spectroscopic techniques. The synthesized nanostructure material was tested for decontaminating water polluted with Congo red, using visible light irradiation. Within 60 min of irradiation, Cd0.1Cu0.90Bi2O4 exhibited 91 % degradation of Congo red, while Cd0.05Cu0.95Bi2O4 and Cd0.15Cu0.85Bi2O4 showed degradation rates of 80 % and 86 % respectively. In contrast, the pure CuBi2O4 had a lower photo degradation rate of 70 % over 70 min of visible light irradiation. Among the synthesized materials, Cd0.1Cu0.90Bi2O4 demonstrated the highest efficiency, require the shortest time to achieve significant degradation. Additionally, the impact of various parameters such as dosage, initial concentration, hydrogen peroxide, and salts on the photo-catalytic degradation of the dye has been studied. Consequently, it can be concluded that the use of hierarchical porous Cd0.1Cu0.90Bi2O4 photocatalyst holds promising potential in wastewater remediation.

Hybrid deterministic and stochastic approach for dynamic simulation of photoinduced atom-transfer radical polymerization processes with microscopic resolution

Among the various polymerization mechanisms available for producing polymers, photoinduced atom-transfer radical polymerization (photoATRP) stands out as a promising technique. By utilizing light as an external stimulus, photoATRP facilitates the production of well-defined polymers with precise distributions. The demand for advanced polymeric materials synthesis necessitates a deep understanding of polymer chains at the molecular level. As molecular weight distribution (MWD) is a key quality index of polymers, developing models with embedded MWD information holds significance for process design and optimization tasks. In this work, an accelerated hybrid deterministic and stochastic approach is proposed for simulating dynamic photoATRP processes. The proposed approach demonstrates computational efficiency and flexibility, enabling precise predictions for the evolution of both macroscopic and microscopic properties of polymers. An application to a batch photoATRP system model is presented to illustrate the validity and performance of the proposed hybrid approach.

Strongly coupled C@MoSe2@OMWCNT heterostructure as an anode for sodium-ion batteries

MoSe2, with its extraordinary theoretical capacity, has emerged as a profoundly auspicious anode material for Sodium-ion Batteries (SIBs). However, the actual realization of SIBs encounters hurdles arising from insufficient electron and ion transportation capabilities, along with the irreversible transformation of Mo/Na2Se into MoSe2, eventually substituted by Mo/Se. In this investigation, By employing Mo-based complexes, we have achieved a triumphant synthesis of C@MoSe2@OMWCNT (oxidized multiwall carbon nanotubes) materials, wherein OMWCNTs serve as the fundamental substrate. Theoretical analysis has revealed that the utilization of OMWCNTs not only enhances the structural stability of the anode materials but also improves the electrical conductivity and Na+ ion mobility (the Na+ diffusion barrier: (MoSe2) 0.91 eV vs (C@MoSe2@OMWCNT) 0.41 eV) of the C@MoSe2@OMWCNT. These properties make C@MoSe2@OMWCNT a promising candidate for the development of high-performance SIBs. Furthermore, the Ex-situ Transmission Electron Microscopy (TEM) examination, unveils the emergence of Se and MoSe2 within the C@MoSe2@OMWCNT. The findings indicate that the outer carbon coating layer efficiently prevents contact between Se and the electrolyte, thereby impeding the formation of polyselenides. When C@MoSe2@OMWCNT is employed as the anode for the SIB, it exhibits exceptional cycle stability, with a capacity of 303 mA h g−1 and 189 mA h g−1 after 500 and 3000 cycles, respectively, under a current density of 5 A g−1. Overall, this investigation provides valuable insights into the design and synthesis of advanced anode materials for SIBs, which could have significant implications for the development of next-generation energy storage devices.

Synthesis of silver nanoparticles using modified lignin as a reducing agent

The emergence and spread of microorganisms, posing a significant threat to public health globally, highlights the urgent need for sustainable solutions to combat pathogens. As a result, green synthesis has garnered increasing attention as an eco-friendly and effective approach to developing antimicrobial materials. This study explores the potential of aminated lignin as an alternative material for synthesizing silver nanoparticles, comparing its performance with commonly used kraft lignin. A one-pot green method was successfully employed to synthesize silver nanoparticles using both lignin types. By incorporating amine groups, lignin demonstrated heightened efficacy as a reducing agent, leading to a nearly fourfold increase in the concentration of silver nanoparticles. The silver nanoparticles obtained using aminated lignin displayed an average crystallite size of 50 nm and demonstrated a more uniform morphology, while those obtained using kraft lignin resulted in a smaller crystallite size of 30 nm but a broader nanoparticle size range. The concentration enhancement and improved morphology control underscore the significant impact of using aminated lignin as a reducing agent, emphasizing its potential in advanced materials synthesis. These results provide valuable insights into the utilization of amine-terminated lignin in nanoparticle synthesis and its potential in diverse applications.

P-n heterogeneous Sb2S3/SnO2 quantum dot anchored reduced graphene oxide nanosheets for high-performance lithium-ion batteries.

Antimony sulfide (Sb2S3) has a high theoretical specific capacity due to its two reaction mechanisms of conversion and alloying during the Li+-(de)intercalation process, thus becoming a promising lithium-ion battery (LIB) anode material. However, its poor inherent conductivity and large volume expansion during repeated Li+-(de)intercalation processes greatly hinder the in-depth development of Sb2S3 based LIB anode materials. Herein, an Sb2S3/SnO2@rGO composite was prepared by using an interface engineering technique involving metal-containing ionic liquid precursors, in which Sb2S3/SnO2 quantum dots (QDs) as p-n heterojunctions are uniformly anchored on the surface of reduced graphene oxide (rGO). The p-n heterogeneous interface between Sb2S3 and SnO2 QDs induces an internal electric field, promoting the electronic/ion transport during electrochemical reactions, and the QD-sized Sb2S3/SnO2 heterostructure with a larger surface area provides more active sites for Li+-(de)intercalation reactions. In addition, the rGO matrix acts as a buffer to prevent the aggregation of active Sb2S3 and SnO2 QDs, alleviate the volume expansion, and enhance the conductivity of the composite during repeated cycles. These advantages endow the designed Sb2S3/SnO2@rGO electrode with excellent reaction kinetics and good long cycling stability. As an anode material of LIBs, it can still provide a reversible specific capacity of 474 mA h g-1 after 2000 cycles at a high current density of 3.0 A g-1, which is superior to those of most of the previously reported Sb2S3-based carbon materials. The p-n heterostructure construction strategy of nano-metal sulfide/metal oxides in this work can provide inspiration for the design and synthesis of other advanced energy storage materials.

Interfacial Electrochemical Polymerization of PEDOT@Polyoxometalates Thin Films As Electroactive Material for Energy Storage Devices

The urgent need for a decarbonized power sector has been one of the most important motivations to get a full transition from the fossil-fuel energy sources to a sustainable energy future based on renewable energy alternatives. In this regard, energy conversion and storage devices, such as batteries, fuel cells and supercapacitors, play a key role in supplying steady power and energy densities in order to guarantee the current energy demand [1]. Among the different alternatives, the design and synthesis of advanced functional nanostructured materials provide an important route to obtain efficient energy devices with high power densities, stability and remarkable energy densities [2].Conducting polymers (CP) have been extensively exploited in a wide application range as result of their remarkable charge-mobility, electrical conductivity, and the scalable synthesis processes. Additionally, the storage of charge, which occurs by a doping process, has been ideal for application as electrochemical supercapacitors [3]. In addition, the CPs network have provided an interesting electrode material in which other active materials (i.e., graphene, MOF) and redox species can be incorporated to induce additional pseudocapacitive processes in the electrode, enhancing the charge stored. The polyoxometalates (POMs), inorganic heteropolyanions received great attention due to their multielectron redox processes in aqueous media [4].Herein, we have explored the electrosynthesis of composite materials based on PEDOT and polyoxometalates (POMs) employing the electrochemical polymerization at a polarized organic | aqueous liquid | liquid interface (L|L), in which the POM acts as oxidizing agent of EDOT and electroactive specie incorporated in the polymer chain network as dopant. The polymerization process was based on the ion migration-controlled by the potential biasing of the water-oil interface. The resulting thin films show the presence of Mo and W within the polymer as well as the presence of different redox processes associated with the POM incorporated in the PEDOT. The induced pseudocapacitive processes in the composite materials have shown high stability in acid media, making it a good candidate as an electrode material in symmetric supercapacitors.

Soccer Ball‐like Assembly of Edge‐to‐edge Oriented 2D‐silica Nanosheets: A Promising Catalyst Support for High‐Temperature Reforming

AbstractControlled assembly of nanoparticles into well‐defined assembled architectures through precise manipulation of spatial arrangement and interactions allows the development of advanced mesoscale materials with tailored structures, hierarchical functionalities, and enhanced properties. Despite remarkable advancements, the controlled assembly of highly anisotropic 2Dnanosheets is significantly challenging, primarily due to the limited availability of selective edge‐to‐edge connectivity compared to the abundant large faces. Innovative strategies are needed to unlock the full potential of 2D‐nanomaterialsin self‐assembled structures with distinct and desirable properties. This research unveils the discovery of controlled self‐assembly of 2D‐silica nanosheets (2D‐SiNSs) into hollow micron‐sized soccer ball‐like shells (SA‐SiMS). The assembly is driven by the physical flexibility of the 2D‐SiNSs and the differential electricdouble‐layer charge gradient creating electrostatic bias on the edge and face regions. The resulting SA‐SiMS structures exhibit high mechanical stability, even at high‐temperatures, and exhibit excellent performance as catalyst support in the dry reforming of methane. The SA‐SiMS structures facilitate improved mass transport, leading to enhanced reaction rates, while the thin silica shell prevents sintering of small catalyst nanocrystals, thereby preventing coke formation. This discovery sheds light on the controllable self‐assembly of 2D nanomaterials and provides insights into the design and synthesis of advanced mesoscale materials with tailored properties.

Soccer Ball-like Assembly of Edge-to-edge Oriented 2D-silica Nanosheets: A Promising Catalyst Support for High-Temperature Reforming.

Controlled assembly of nanoparticles into well-defined assembled architectures through precise manipulation of spatial arrangement and interactions allows the development of advanced mesoscale materials with tailored structures, hierarchical functionalities, and enhanced properties. Despite remarkable advancements, the controlled assembly of highly anisotropic 2Dnanosheets is significantly challenging, primarily due to the limited availability of selective edge-to-edge connectivity compared to the abundant large faces. Innovative strategies are needed to unlock the full potential of 2D-nanomaterialsin self-assembled structures with distinct and desirable properties. This research unveils the discovery of controlled self-assembly of 2D-silica nanosheets (2D-SiNSs) into hollow micron-sized soccer ball-like shells (SA-SiMS). The assembly is driven by the physical flexibility of the 2D-SiNSs and the differential electricdouble-layer charge gradient creating electrostatic bias on the edge and face regions. The resulting SA-SiMS structures exhibit high mechanical stability, even at high-temperatures, and exhibit excellent performance as catalyst support in the dry reforming of methane. The SA-SiMS structures facilitate improved mass transport, leading to enhanced reaction rates, while the thin silica shell prevents sintering of small catalyst nanocrystals, thereby preventing coke formation. This discovery sheds light on the controllable self-assembly of 2D nanomaterials and provides insights into the design and synthesis of advanced mesoscale materials with tailored properties.

Coupling of reasonable micro-defect structure and multiple chemisorption sites for boosting the K+ storage capacity in dual-carbon potassium ion hybrid capacitors

Construction of hierarchical porous (meso‑microporous) carbonaceous anodes with reasonable-sized defects and rich active sites is important for enhancing K+ storage capacity. Here, we propose a strategy that can expand the microporous defects and synchronously introduce multiple chemisorption sites to synthesize phosphorus-nitrogen double-doped foamed porous carbon (PN-FPC). Interlaced and interconnected macropores in PN-FPC can effectively promote long-range mass transfer, while ultrathin carbon bubble walls with abundant meso‑micropores and chemisorption sites can maximize the utilization of active sites. Density-functional theory (DFT) calculations show that the P, N double-doped synergistically rational micro-defect structure significantly contributes to the reversible adsorption-desorption of K+. More importantly, the potassium-ion hybrid capacitors (PIHCs) composed of P, N double-doped activated porous carbon (PN-FAPC) as cathode and pre-activated PN-FPC as anode exhibited ultra-high energy density (155.6 Wh kg−1), power density (17,000 W kg−1), and ultra-long lifetime (90.9 % capacity retention after 10,000 cycles). This study not only provides new insights for the convenient synthesis of advanced carbonaceous anode materials, but also provides a deeper understanding for revealing the charge storage mechanism of PIHCs.

PH-dependent synthesis of CeO2-ZnO nanocomposite for enhanced environmental remediation of endosulfan and dimethoate pesticides

This research aims to tackle significant challenges related to the synthesis and utilization of advanced nanocomposite materials in environmental remediation, specifically focusing on pesticide degradation. The synthesis of CeO2-ZnO nanocomposites employs both co-precipitation and hydrothermal methods, with the inclusion of the zwitterionic surfactant (SB-12) as a surface modifier. The modulation of pH levels during the synthesis of CeO2-ZnO nanocomposites allows for the optimization of crucial reaction parameters. Notably, it is observed that nanocomposites prepared at pH 9 exhibit the smallest average particle size. To comprehensively characterize these prepared nanocomposites, various analytical techniques such as FTIR, XRD, DR-UV/Vis, TEM/EDS, and Nano particle size analysis are employed. The FTIR results reveal a reduced presence of impurities at higher pH levels. Notably, the CeO2-ZnO nanocomposites synthesized via the hydrothermal method at pH 9 exhibit polyhedral nanostructures. The research's significant contribution lies in the practical application of these nanocomposites for the degradation of highly toxic and persistent organochlorine and organophosphorus pesticides, particularly Endosulfan and Dimethoate. These nanoparticles demonstrate remarkable pesticide degradation capabilities, with a particular emphasis on their high effectiveness against Endosulfan. The potential implications of this work extend to areas such as environmental protection, sustainable agriculture, and the remediation of pesticide-contaminated ecosystems.

Polymerized PEI-modified lignin polyphenolic materials by acid hydrolysis-phase separation for removal of Cr (VI) from industrial wastewater

Cr (VI) accumulates in an aqueous environment and exhibits huge harm to human health and the ecological system. Developed lignin biomass materials are complicated to prepare and have limited properties, and advances in lignin phenolic modification are lacking. Herein, an aminated poplar lignin-pyrogallol (PLP-PEI) with a simple design and adjustable phenolic hydroxyl content was developed using the acid hydrolysis-phase separation (AH-PS) method, and modified by the atom transfer radical polymerization (ATRP) strategy. Through diverse characterization analysis, the structural changes of PLP-PEI in the step-by-step synthesis process were monitored. An effective biomass capture system (Bio-Cap) was shown via systematically investigating the adsorption behaviors of Cr (VI) on PLP-PEI under various environmental conditions. Benefiting from introducing phenolic hydroxyl and amino groups, PLP-PEI demonstrated efficient adsorption capacity (598.80 mg/g for Cr (VI)). Additionally, the material also exhibited advantages, including monomeric chemisorption properties, strong reduction capability, and stable regeneration properties. Multiple driving forces were involved in the capture and removal process of Cr (VI), including complexation and electrostatic interaction. The low-cost natural biomass resources supported the industrial-scale synthesis and practical application of advanced aminated lignin polyphenol material, which showed outstanding advantages and enormous potential in the field of water environmental restoration.

Recent Developments in Nanostructured Materials for Supercapacitor Electrodes

This review focuses on nanostructures-based systems and aims to provide a comprehensive overview of recent advancements in energy storage technologies and modified energy storage materials. The transition towards a sustainable and carbon-free energy system hinges on the progress of efficient and safe energy storage technologies. Supercapacitors have garnered significant interest in diverse energy storage applications due to their rapid charge/discharge rates, high power density, and extended cycle life. Nanostructures have conclusively demonstrated their capability to significantly enhance supercapacitor electrodes' performance. MXene, an innovative category of 2D materials, has emerged as a promising candidate for energy storage applications due to its substantial surface area, exceptional electrical conductivity, and versatile characteristics. Supercapacitors, nanostructures, and MXene are the main topics of the research articles and reviews in this special issue, highlighting recent developments in the design, synthesis, and characterization of advanced energy storage materials and devices. Additionally, this study presents an in-depth investigation of various carbon-based nanomaterials, their synthesis techniques, and their performance in supercapacitors. It also emphasizes the potential of recycling waste materials for developing high-performance nanomaterials for energy storage applications. Finally, this review encourages further research and development of advanced energy storage technologies by giving readers a thorough overview of the current state-of-the-art and future directions in this rapidly expanding sector.

Exploring the Impact of DAHP Impregnation on Activated Carbon Fibers for Efficient Charge Storage and Selective O2 Reduction to Peroxide

Understanding the properties and behavior of carbon materials is of paramount importance in the pursuit of sustainable energy solutions and technological advancements. As versatile and abundant resources, carbon materials play a central role in various energy conversion and storage applications, making them essential components in the transition toward a greener and more efficient future. This study explores the impact of diammonium hydrogen phosphate (DAHP) impregnation on activated carbon fibers (ACFs) for efficient energy storage and conversion applications. The viscose fibers were impregnated with varying DAHP concentrations, followed by carbonization and activation processes. The capacitance measurements were conducted in 6 mol dm−3 KOH, 0.5 mol dm−3 H2SO4, and 2 mol dm−3 KNO3 solutions, while the oxygen reduction reaction (ORR) measurements were performed in O2-saturated 0.1 mol dm−3 KOH solution. We find that the presented materials display specific capacitances up to 160 F g−1 when the DAHP concentration is in the range of 1.0 to 2.5%. Moreover, for the samples with lower DAHP concentrations, highly selective O2 reduction to peroxide was achieved while maintaining low ORR onset potentials. Thus, by impregnating viscose fibers with DAHP, it is possible to tune their electrochemical properties while increasing the yield, enabling the more sustainable and energy-efficient synthesis of advanced materials for energy conversion applications.

Ultra-fast high-temperature synthesis and densification of high-entropy diborides and diboride-carbide ceramics

The strong covalent bonds and low self-diffusion coefficients of high-entropy diboride (HEBs) and diboride-carbide (HEB-HEC) ceramics render their densification difficult, which limits their applications. Here, we used an ultra-fast high-temperature sintering technique to synthesize and densify several HEBs and HEB-HEC (containing 5–8 cations) ceramics within an isothermal duration of 1 min and a total sintering period of 6 min. All ceramics formed a single-phase or dual-phase high-entropy solid solution, and showed high density, high hardness and good fracture toughness. The rapid densification mechanisms were determined, and the preferential dissolution of metal cations in HEB and HEC phases was explained using a simplified ideal solution model. A good fracture toughness in the range of 3.6-5.4 MPa·m1/2 resulted from crack deflection or blunting and bridging of the rod-like diboride or boron-rich phase. This paper presents a simple, economical, and efficient method for the synthesis and densification of high-entropy ceramics and other advanced materials.

Visible Light Photoiniferter Polymerization for Dispersity Control in High Molecular Weight Polymers

AbstractThe synthesis of polymers with high molecular weights, controlled sequence, and tunable dispersities remains a challenge. A simple and effective visible‐light controlled photoiniferter reversible addition‐fragmentation chain transfer (RAFT) polymerization is reported here to realize this goal. Key to this strategy is the use of switchable RAFT agents (SRAs) to tune polymerization activities coupled with the inherent highly living nature of photoiniferter RAFT polymerization. The polymerization activities of SRAs were in situ adjusted by the addition of acid. In addition to a switchable chain‐transfer coefficient, photolysis and polymerization kinetic studies revealed that neutral and protonated SRAs showed different photolysis and polymerization rates, which is unique to photoiniferter RAFT polymerization in terms of dispersity control. This strategy features no catalyst, no exogenous radical source, temporal regulation by visible light, and tunable dispersities in the unprecedented high molecular weight regime (up to 500 kg mol−1). Pentablock copolymers with three different dispersity combinations were also synthesized, highlighting that the highly living nature was maintained even for blocks with large dispersities. Tg was lowered for high‐dispersity polymers of similar MWs due to the existence of more low‐MW polymers. This strategy holds great potential for the synthesis of advanced materials with controlled molecular weight, dispersity and sequence.

Visible Light Photoiniferter Polymerization for Dispersity Control in High Molecular Weight Polymers.

The synthesis of polymers with high molecular weights, controlled sequence, and tunable dispersities remains a challenge. A simple and effective visible-light controlled photoiniferter reversible addition-fragmentation chain transfer (RAFT) polymerization is reported here to realize this goal. Key to this strategy is the use of switchable RAFT agents (SRAs) to tune polymerization activities coupled with the inherent highly living nature of photoiniferter RAFT polymerization. The polymerization activities of SRAs were in situ adjusted by the addition of acid. In addition to a switchable chain-transfer coefficient, photolysis and polymerization kinetic studies revealed that neutral and protonated SRAs showed different photolysis and polymerization rates, which is unique to photoiniferter RAFT polymerization in terms of dispersity control. This strategy features no catalyst, no exogenous radical source, temporal regulation by visible light, and tunable dispersities in the unprecedented high molecular weight regime (up to 500 kg mol-1 ). Pentablock copolymers with three different dispersity combinations were also synthesized, highlighting that the highly living nature was maintained even for blocks with large dispersities. Tg was lowered for high-dispersity polymers of similar MWs due to the existence of more low-MW polymers. This strategy holds great potential for the synthesis of advanced materials with controlled molecular weight, dispersity and sequence.