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2023 Volume 42 Issue 6
2023, 42(6): 100067
doi: 10.1016/j.cjsc.2023.100067
Abstract:
2023, 42(6): 100068
doi: 10.1016/j.cjsc.2023.100068
Abstract:
Lowering the cost while maintaining the highly catalytic performance is greatly beneficial for the development of commercial fuel cells and metal-air batteries. Compared with platinum, palladium holds a stronger oxygen affinity and high abundance on earth, endowing it a promising alternative to platinum in anion-exchange membrane fuel cells. However, the sluggish oxygen reduction reaction of palladium still remains a great issue and requires the design of stable and efficient palladium-based electrocatalysts. Here, we report the solvothermal/hydrothermal reduction method to prepare a series of PdAgx nanowires. The prepared PdAgx NWs exhibit hollow structure, which greatly improves the utilization of Pd atoms, offering an outstanding ORR performance. Specifically, PdAg2 NWs exhibit an onset potential of 0.92 V and mass activity of 350.7 mA mgPd-1 at 0.7 V vs. RHE for ORR in 0.1 M KOH solution. This work provides a novel approach for the construction of hollow NWs and their subsequent applications in other electrocatalytic reactions.
Lowering the cost while maintaining the highly catalytic performance is greatly beneficial for the development of commercial fuel cells and metal-air batteries. Compared with platinum, palladium holds a stronger oxygen affinity and high abundance on earth, endowing it a promising alternative to platinum in anion-exchange membrane fuel cells. However, the sluggish oxygen reduction reaction of palladium still remains a great issue and requires the design of stable and efficient palladium-based electrocatalysts. Here, we report the solvothermal/hydrothermal reduction method to prepare a series of PdAgx nanowires. The prepared PdAgx NWs exhibit hollow structure, which greatly improves the utilization of Pd atoms, offering an outstanding ORR performance. Specifically, PdAg2 NWs exhibit an onset potential of 0.92 V and mass activity of 350.7 mA mgPd-1 at 0.7 V vs. RHE for ORR in 0.1 M KOH solution. This work provides a novel approach for the construction of hollow NWs and their subsequent applications in other electrocatalytic reactions.
2023, 42(6): 100069
doi: 10.1016/j.cjsc.2023.100069
Abstract:
The poor sensitivity of metal-oxide (MO) sensing material at room temperature can be enhanced by the modification of noble metal catalysts. However, the large size and uncontrollable morphology of metal nanoparticles (NPs) compromise the catalytic activity and selectivity. Downsizing metal NPs to the atomic level is a promising solution because it offers high activity and selectivity. Nevertheless, a facile and universal approach for stable loading atomic-level metal on MO-based sensing materials is still challenging. Herein, we present a strategy to construct synergetic coordination interface for uniform loading of atomic-level metal catalysts on MO-based gas sensing materials using a difunctional mediator layer. In this work, atomically dispersed Pt catalysts are coordinately anchored on ZnO nanorods (NRs) using polydopamine (PDA) as a mediator. As a result, compared with pristine ZnO NRs, a six-fold enhanced response of 18,489% is achieved toward 100 ppm NO2 on 0.20 wt% Pt-ZnO@PDA-1.5 nm, and the selectivity is also promoted. Such sensitivity is higher than that of most reported noble metal-modified MO NO2-sensing materials. This work provides a simple and general strategy for building highly sensitive and selective gas-sensing materials using atomic-level noble metal catalyst.
The poor sensitivity of metal-oxide (MO) sensing material at room temperature can be enhanced by the modification of noble metal catalysts. However, the large size and uncontrollable morphology of metal nanoparticles (NPs) compromise the catalytic activity and selectivity. Downsizing metal NPs to the atomic level is a promising solution because it offers high activity and selectivity. Nevertheless, a facile and universal approach for stable loading atomic-level metal on MO-based sensing materials is still challenging. Herein, we present a strategy to construct synergetic coordination interface for uniform loading of atomic-level metal catalysts on MO-based gas sensing materials using a difunctional mediator layer. In this work, atomically dispersed Pt catalysts are coordinately anchored on ZnO nanorods (NRs) using polydopamine (PDA) as a mediator. As a result, compared with pristine ZnO NRs, a six-fold enhanced response of 18,489% is achieved toward 100 ppm NO2 on 0.20 wt% Pt-ZnO@PDA-1.5 nm, and the selectivity is also promoted. Such sensitivity is higher than that of most reported noble metal-modified MO NO2-sensing materials. This work provides a simple and general strategy for building highly sensitive and selective gas-sensing materials using atomic-level noble metal catalyst.
2023, 42(6): 100070
doi: 10.1016/j.cjsc.2023.100070
Abstract:
The development of metal-organic frameworks (MOFs) with highly efficient adsorption and separation of acetylene is very important and challenging in chemical industry due to the explosive nature of acetylene. Porous MOFs can be constructed by inserting a second auxiliary ligand, which allows the use of large ligands to construct non-interpenetrated structures and increase pore utilization. Herein, SNNU-205 is successfully synthesized, which connects two sets of interpenetrated structures to form a double walled cage-within-cage structure by using the introduction of a second auxiliary ligand. The modified pore environment enables SNNU-205 to efficiently selectively adsorb C2H2 over CO2. At 298 K and 1 atm, SNNU-205 can uptake much more C2H2 (76.3 cm3 g1 ) than CO2 (47.3 cm3 g1 ), resulting in a high substance ratio of C2H2-to-CO2 (1.6). More importantly, the ideal adsorbed solution theory selectivity calculations and column breakthrough tests further indicate SNNU-205 to be promising adsorbents for C2H2 adsorption and purification.
The development of metal-organic frameworks (MOFs) with highly efficient adsorption and separation of acetylene is very important and challenging in chemical industry due to the explosive nature of acetylene. Porous MOFs can be constructed by inserting a second auxiliary ligand, which allows the use of large ligands to construct non-interpenetrated structures and increase pore utilization. Herein, SNNU-205 is successfully synthesized, which connects two sets of interpenetrated structures to form a double walled cage-within-cage structure by using the introduction of a second auxiliary ligand. The modified pore environment enables SNNU-205 to efficiently selectively adsorb C2H2 over CO2. At 298 K and 1 atm, SNNU-205 can uptake much more C2H2 (76.3 cm3 g1 ) than CO2 (47.3 cm3 g1 ), resulting in a high substance ratio of C2H2-to-CO2 (1.6). More importantly, the ideal adsorbed solution theory selectivity calculations and column breakthrough tests further indicate SNNU-205 to be promising adsorbents for C2H2 adsorption and purification.
2023, 42(6): 100071
doi: 10.1016/j.cjsc.2023.100071
Abstract:
Photochemical catalytic processes can reduce the activation energy so that reactions can occur under milder conditions. However, it is still unknown whether photochemical effects are present in photothermal catalysis over conventional transition metal materials. Herein, the representative photothermal CO2 hydrogenation catalyst, Ni@p-SiO2, is employed as a model system to quantitatively probe the contribution of photochemical effect. Through a series of catalytic and photophysical characterizations, it is found that negligible photochemical effect in the ultraviolet-visible region can be observed for the traditional Ni-based catalyst. The results of photoelectrochemistry (PEC) test further confirm that no apparent photochemical effect is present for the Ni@p-SiO2 catalyst in the aqueous-phase environment. It has been further evidenced that the photochemical contributions can be significantly amplified by introducing plasmonic metals, such as Au, into the system. This work provides a guideline for the design and construction of efficient synergetic photothermal-photochemical catalytic systems.
Photochemical catalytic processes can reduce the activation energy so that reactions can occur under milder conditions. However, it is still unknown whether photochemical effects are present in photothermal catalysis over conventional transition metal materials. Herein, the representative photothermal CO2 hydrogenation catalyst, Ni@p-SiO2, is employed as a model system to quantitatively probe the contribution of photochemical effect. Through a series of catalytic and photophysical characterizations, it is found that negligible photochemical effect in the ultraviolet-visible region can be observed for the traditional Ni-based catalyst. The results of photoelectrochemistry (PEC) test further confirm that no apparent photochemical effect is present for the Ni@p-SiO2 catalyst in the aqueous-phase environment. It has been further evidenced that the photochemical contributions can be significantly amplified by introducing plasmonic metals, such as Au, into the system. This work provides a guideline for the design and construction of efficient synergetic photothermal-photochemical catalytic systems.
2023, 42(6): 100087
doi: 10.1016/j.cjsc.2023.100087
Abstract:
Interfacial defect is one of the main hurdles to impede the improvement of efficiency and stability of perovskite solar cells (PSCs). Additionally, the ultraviolet (UV) irradiate induces the generation of deep defects, and further accelerate the decomposition of perovskite films. Thus, the interfacial modification is crucial to improve the efficiency and stability of PSCs. Here, the salicylic acid (SA) as a multifunctional interface material is employed to modify the interface of mesoporous cerium oxide (m-CeOx) and perovskite. The introduced SA molecules can interact with Ce in m-CeOx and Pb in perovskite through carboxylic acid functional groups to passivate interfacial defects and promote interfacial electron extraction and transport. The PSC with SA modification exhibits an improved power conversion efficiency (PCE) of 23.33%. More importantly, the SA can absorb UV light and reduce the damage of UV light to perovskite film, then improving the UV stability and overall stability of devices. This work provides a novel insight to design the interfacial modification materials for preparing efficient and stable PSCs.
Interfacial defect is one of the main hurdles to impede the improvement of efficiency and stability of perovskite solar cells (PSCs). Additionally, the ultraviolet (UV) irradiate induces the generation of deep defects, and further accelerate the decomposition of perovskite films. Thus, the interfacial modification is crucial to improve the efficiency and stability of PSCs. Here, the salicylic acid (SA) as a multifunctional interface material is employed to modify the interface of mesoporous cerium oxide (m-CeOx) and perovskite. The introduced SA molecules can interact with Ce in m-CeOx and Pb in perovskite through carboxylic acid functional groups to passivate interfacial defects and promote interfacial electron extraction and transport. The PSC with SA modification exhibits an improved power conversion efficiency (PCE) of 23.33%. More importantly, the SA can absorb UV light and reduce the damage of UV light to perovskite film, then improving the UV stability and overall stability of devices. This work provides a novel insight to design the interfacial modification materials for preparing efficient and stable PSCs.
2023, 42(6): 100090
doi: 10.1016/j.cjsc.2023.100090
Abstract:
Photocatalytic hydrogen evolution reaction (HER) represents one of the most promising technologies for sustainable development. Even though metal-organic framework (MOF), comprising rich topologies and tunable functionalities, is getting attention as a new generation of photocatalyst, a majority of them only provide unclear active sites along with the use of external noble-metal based photosensitizers and environmentally unfriendly scavengers. Therefore, it is urged to develop MOFs possessing structurally unambiguous active sites along with inherent photosensitizing units and execute photocatalytic HER with greener sacrificial reagents. Herein, we report a UiO-66-type framework, namely UiO-66-dcbdt-Cd (dcbdt2- = 1,4-dicarboxylatebenzene-2,3-dithiol), bearing Cd-thiocatecholato moieties as intrinsic photosensitizing units and structurally well-defined active sites for photocatalytic HER in H2O. UiO-66-dcbdt-Cd gave the best HER yield of 5.29 mmol g-1 and rate of 1.32 mmol g-1 h-1, outperforming the negligible HER performance of pristine metal-free UiO-66-dcbdt. This work provides insight to manipulation of thiocatecholate functionalities inside MOFs to construct inherent photosensitizing units as well as stable structurally unambiguous active sites for sustainable photocatalytic applications.
Photocatalytic hydrogen evolution reaction (HER) represents one of the most promising technologies for sustainable development. Even though metal-organic framework (MOF), comprising rich topologies and tunable functionalities, is getting attention as a new generation of photocatalyst, a majority of them only provide unclear active sites along with the use of external noble-metal based photosensitizers and environmentally unfriendly scavengers. Therefore, it is urged to develop MOFs possessing structurally unambiguous active sites along with inherent photosensitizing units and execute photocatalytic HER with greener sacrificial reagents. Herein, we report a UiO-66-type framework, namely UiO-66-dcbdt-Cd (dcbdt2- = 1,4-dicarboxylatebenzene-2,3-dithiol), bearing Cd-thiocatecholato moieties as intrinsic photosensitizing units and structurally well-defined active sites for photocatalytic HER in H2O. UiO-66-dcbdt-Cd gave the best HER yield of 5.29 mmol g-1 and rate of 1.32 mmol g-1 h-1, outperforming the negligible HER performance of pristine metal-free UiO-66-dcbdt. This work provides insight to manipulation of thiocatecholate functionalities inside MOFs to construct inherent photosensitizing units as well as stable structurally unambiguous active sites for sustainable photocatalytic applications.
2023, 42(6): 100092
doi: 10.1016/j.cjsc.2023.100092
Abstract:
Hollow structured composite can enhance the structural stability of metal sulfide anode by accommodating its volume variation, while the performance is still hindered by its poor electron/ion conductivity. Herein, we develop a hierarchical hollow structure to achieve superior electrochemical performance, from which a MOF-to-MOF conversion is utilized to generate hollow Zn-Co1-xS/C composite followed with additional carbon coating layer. For potassium storage, as-prepared hollow Zn-Co1-xS/C@C composite displays high capacities of 375 mA h g-1 after 100 cycles at 0.2 A g-1 and 201 mA h g-1 after 500 cycles at 1 A g-1 . Moreover, it also manifests outstanding rate capability of 200 mA h g-1 at 10 A g-1, outperforming hollow Co1-xS@C and majority of the reported cobalt-based anodes. With illustration by kinetics analysis and theoretical calculation, both of Zn doping and internal carbon matrix are conductive to promote the charge transportation ability of Co1-xS, thus accounting for the good cycling behavior and excellent rate capacity of hierarchical hollow Zn-Co1-xS/C@C composite.
Hollow structured composite can enhance the structural stability of metal sulfide anode by accommodating its volume variation, while the performance is still hindered by its poor electron/ion conductivity. Herein, we develop a hierarchical hollow structure to achieve superior electrochemical performance, from which a MOF-to-MOF conversion is utilized to generate hollow Zn-Co1-xS/C composite followed with additional carbon coating layer. For potassium storage, as-prepared hollow Zn-Co1-xS/C@C composite displays high capacities of 375 mA h g-1 after 100 cycles at 0.2 A g-1 and 201 mA h g-1 after 500 cycles at 1 A g-1 . Moreover, it also manifests outstanding rate capability of 200 mA h g-1 at 10 A g-1, outperforming hollow Co1-xS@C and majority of the reported cobalt-based anodes. With illustration by kinetics analysis and theoretical calculation, both of Zn doping and internal carbon matrix are conductive to promote the charge transportation ability of Co1-xS, thus accounting for the good cycling behavior and excellent rate capacity of hierarchical hollow Zn-Co1-xS/C@C composite.
2023, 42(6): 100093
doi: 10.1016/j.cjsc.2023.100093
Abstract:
In recent years, persulfate (PS)-based advanced oxidation processes (AOPs) have become a hot research topic for degrading environmental pollutants due to their excellent oxidation capacity, selectivity, and stability. PS-AOPs can generate sulfate radicals (SO4i) with strong oxidation ability, but single PS produces limited or no radicals. Therefore, activation of PS by energy input or catalyst dosing is used to improve its oxidation performance. However, the addition of disposable catalyst not only causes a waste of resources, but also may lead to secondary pollution. Therefore, magnetically separable catalysts for activating PS have received widespread attention due to their reusability. Although there are few literature reviews on the activation of PS by carbon- or iron-based magnetic materials, the mechanism analysis of the activation of PS by magnetic materials to degrade pollutants is not deep enough, and the discussion of material types is not comprehensive and detailed. Moreover, the discussion of magnetic materials in terms of recycling properties is lacking. Therefore, this review firstly summarizes and analyzes the mechanism of magnetically separable catalysts activating PS to degrade pollutants. Then, the research progress of zero-valent iron (ZVI, Fe0)-based, iron oxide-based, bimetallic oxide-based, and other magnetically separable catalyst is introduced, and the tailoring engineering approaches and reusability of magnetically separable catalysts are discussed. Finally, some possible material optimization suggestions are proposed in this paper. In conclusion, this review is expected to provide useful insights for improving the performance and reusability of magnetically separable materials activated PS in the future.
In recent years, persulfate (PS)-based advanced oxidation processes (AOPs) have become a hot research topic for degrading environmental pollutants due to their excellent oxidation capacity, selectivity, and stability. PS-AOPs can generate sulfate radicals (SO4i) with strong oxidation ability, but single PS produces limited or no radicals. Therefore, activation of PS by energy input or catalyst dosing is used to improve its oxidation performance. However, the addition of disposable catalyst not only causes a waste of resources, but also may lead to secondary pollution. Therefore, magnetically separable catalysts for activating PS have received widespread attention due to their reusability. Although there are few literature reviews on the activation of PS by carbon- or iron-based magnetic materials, the mechanism analysis of the activation of PS by magnetic materials to degrade pollutants is not deep enough, and the discussion of material types is not comprehensive and detailed. Moreover, the discussion of magnetic materials in terms of recycling properties is lacking. Therefore, this review firstly summarizes and analyzes the mechanism of magnetically separable catalysts activating PS to degrade pollutants. Then, the research progress of zero-valent iron (ZVI, Fe0)-based, iron oxide-based, bimetallic oxide-based, and other magnetically separable catalyst is introduced, and the tailoring engineering approaches and reusability of magnetically separable catalysts are discussed. Finally, some possible material optimization suggestions are proposed in this paper. In conclusion, this review is expected to provide useful insights for improving the performance and reusability of magnetically separable materials activated PS in the future.
2023, 42(6): 100094
doi: 10.1016/j.cjsc.2023.100094
Abstract:
