Surface modification and enhanced photocatalytic CO2 reduction performance of TiO2: a review

Recent progress on earth abundant electrocatalysts for oxygen evolution reaction (OER) in alkaline medium to achieve efficient water splitting - A review

A review of TiO2 nanostructured catalysts for sustainable H2 generation

Water splitting is one of the ideal technologies to meet the ever increasing demands of energy. Many materials have aroused great attention in this field. The family of nickel-based sulfides is one of the examples that possesses interesting properties in water-splitting fields. In this paper, a controllable and simple strategy to synthesize nickel sulfides was proposed. First, we fabricated NiS2 hollow microspheres via a hydrothermal process. After a precise heat control in a specific atmosphere, NiS porous hollow microspheres were prepared. NiS2 was applied in hydrogen evolution reaction (HER) and shows a marvelous performance both in acid medium (an overpotential of 174 mV to achieve a current density of 10 mA/cm2 and the Tafel slope is only 63 mV/dec) and in alkaline medium (an overpotential of 148 mV to afford a current density of 10 mA/cm2 and the Tafel slope is 79 mV/dec). NiS was used in oxygen evolution reaction (OER) showing a low overpotential of 320 mV to deliver a current density of 10 mA/cm2,...

Targeted Synthesis of Unique Nickel Sulfide (NiS, NiS2) Microarchitectures and the Applications for the Enhanced Water Splitting System

The ever-increasing demand for clean and renewable power sources has sparked intensive research on water splitting to produce hydrogen, in which the exploration of electrocatalysts is the central issue. Herein, a new strategy, metal–organic framework template-directed fabrication of hierarchically structured Co3O4@X (X = Co3O4, CoS, C, and CoP) electrocatalysts for efficient oxygen evolution reaction (OER) is developed, where Co3O4@X are derived from cobalt carbonatehydroxide@zeolitic-imidazolate-framework-67 (CCH@ZIF-67). Unique hierarchical structure and synergistic effect of resulting catalysts endow abundant exposed active sites, facile ion diffusion path, and improved conductivity, being favorable for improving catalytic activity of them. Consequently, these derivatives Co3O4@X reveal highly efficient electrocatalytic performance with long-term durability for the OER, much superior to previously reported cobalt-based catalysts as well as the Ir/C catalyst. Particularly, Co3O4@CoP exhibits the highest electrocatalytic capability with the lower overpotential of 238 mV at the current density of 10 mA cm−2. Furthermore, Co3O4@X can also efficiently catalyze other small molecules through electro-oxidation reaction (e.g., glycerol, methanol, or ethanol). It is expected that the strategy presented here can be extended to the fabrication of other composite electrode materials with hierarchical structures for more efficient water splitting.

MOF Template‐Directed Fabrication of Hierarchically Structured Electrocatalysts for Efficient Oxygen Evolution Reaction

An efficient NiS@N/S-C hybrid oxygen evolution electrocatalyst derived from metal-organic framework

Abstract Understanding the function of moisture on perovskite is challenging since the random environmental moisture strongly disturbs the perovskite structure. Here, we develop various N 2 -protected characterization techniques to comprehensively study the effect of moisture on the efficient cesium, methylammonium, and formamidinium triple-cation perovskite (Cs 0.05 FA 0.75 MA 0.20 )Pb(I 0.96 Br 0.04 ) 3 . In contrast to the secondary measurements, the established air-exposure-free techniques allow us directly monitor the influence of moisture during perovskite crystallization. We find a controllable moisture treatment for the intermediate perovskite can promote the mass transportation of organic salts, and help them enter the buried bottom of the films. This process accelerates the quasi-solid-solid reaction between organic salts and PbI 2 , enables a spatially homogeneous intermediate phase, and translates to high-quality perovskites with much-suppressed defects. Consequently, we obtain a champion device efficiency of approaching 24% with negligible hysteresis. The devices exhibit an average T 80 -lifetime of 852 h (maximum 1210 h) working at the maximum power point. 

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Moisture-triggered fast crystallization enables efficient and stable perovskite solar cells

Synthesis of spindle-shaped AgI/TiO 2 nanoparticles with enhanced photocatalytic performance

Synthesis and characterization of carbon nanotubes-treated Ag@TiO2 core–shell nanocomposites with highly enhanced photocatalytic performance

Novel, visible light driven CNTs-TiO2@AgI hybrid materials were synthesized by a simple solvothermaldissolution-precipitation method, during which the acid vapor treated carbon nanotubes (CNTs) as template, AgI as sensitizer and TiO2 as the bridge unified them to form a ternary composite. The morphology and chemical components of as-prepared samples were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). XRD and XPS characterizations indicated that anatase TiO2 and crystal AgI co-existed in the composite. HRTEM demonstrated CNTs were decorated with well-dispersed AgI and TiO2 nanoparticles (NPs), and TiO2 had an intimate connection with both AgI and CNTs. Diffusive reflectance UV-vis spectroscopy of CNTs-TiO2@AgI nanocomposite was extended to the whole UV-visible region due to adding of CNTs and AgI NPs. Degradation of Rhodamine B (RhB) polluted water using CNTs-TiO2@AgI NPs was carried out under visible light irradiation, and it showed higher degradation efficiency than CNTs-TiO2, TiO2@AgI, and CNTs@AgI NPs. The primary reason for the enhanced photocatalytic property was attributed to the synergic effect in CNTs-TiO2@AgI, which included the good adsorption ability and electrical conductivity of CNTs as well as the intimate connection and hetero-junctions among AgI, TiO2, and CNTs. Meanwhile, the as-prepared hybrid materials can be easily separated and reclaimed from the liquid phase, and the recycling tests indicated CNTs-TiO2@AgI had renewable performance.

Liu Yang

Papers

An efficient NiS@N/S-C hybrid oxygen evolution electrocatalyst derived from metal-organic framework

Moisture-triggered fast crystallization enables efficient and stable perovskite solar cells

Synthesis of spindle-shaped AgI/TiO 2 nanoparticles with enhanced photocatalytic performance

Synthesis and characterization of carbon nanotubes-treated Ag@TiO2 core–shell nanocomposites with highly enhanced photocatalytic performance

Fabrication of carbon nanotube-loaded TiO2@AgI and its excellent performance in visible-light photocatalysis