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The use of alkali-activated slag (AAS), an eco-friendly cementitious material, to replace ordinary Portland cement in construction can reduce the energy consumption, CO2 emissions, and solid dust pollution and promote the recycling of ground granulated blast furnace slag, which represents an industrial solid waste. However, the creep of AAS concrete is a critical long-term property that has rarely been investigated. Creep is related to the structural safety, including that of large pre-stressed concrete structures. AAS concrete exhibits a higher creep and lower elasticity modulus compared to OPC concrete, and the addition of fibres is an effective solution to this problem. In this study, the effects of fibre dosage and stress-strength ratio on the creep properties of polypropylene (PP) fibre-reinforced AAS (FRAAS) concrete were investigated. Thirty-two creep samples with four fibre dosages and four stress–strength ratios were subjected to tests for approximately 350 d. The PP FRAAS concrete did not exhibit any significant linear creep behaviour. With the increase of fibre dosage, the inhibition effect of fibres first became stronger and then became weaker. The inhibition effect of the fibres was gradually intensified with the increasing stress–strength ratio. As the fibre dosage increased from 0 to 0.9%, the creep coefficient gradually decreased. Based on the experimental results, a method of predicting the creep of PP FRAAS concrete was developed. [ABSTRACT FROM AUTHOR]

Cocatalysts play important roles in photocatalytic and photoelectrochemical water splitting reactions. However, the formation of well-defined junctions between low dimensional semiconductors and cocatalysts is still challenging. In this study, CdS nanorod photoanodes loaded with cobalt phosphate (CoPi) cocatalyst were synthesized by a facile two-step route, in which CdS nanorods were prepared using a hydrothermal method followed by photo-assisted electrodeposition of CoPi. It was found that the formation of intimate junctions between CoPi and CdS nanorods in the form of Co–S bonding effectively facilitated the charge separation and lowered the activation energy of the water oxidation reaction. This resulted in highly efficient and stable photoelectrochemical water splitting on the CdS photoanode. The optimal CdS/CoPi photoanode showed a maximum photocurrent of 4.7 mA/cm2 at 0 V versus reversible hydrogen electrode under an AM 1.5 G solar simulator, which was 5.5-fold higher than that of bare CdS photoanode. This work expands the potential application of the cocatalyst CoPi in CdS photoanode systems and improves our understanding of the nature of cocatalysts with well-defined interface junctions in semiconductors. Well-defined interfacial junction with Co–S bonding over cobalt phosphate cocatalyzed CdS nanorod photoanode facilitates the charge separation and lowers the activation energy, thus achieving a considerable photocurrent of 4.7 mA/cm2 at 0 V vs. RHE. [ABSTRACT FROM AUTHOR]