As the first example of a photocatalytic system for splitting water without additional cocatalysts and photosensitizers, the comparatively cost-effective Cu I -based MOF, Cu-I-bpy (bpy=4,4'-bipyridine) exhibited highly efficient photocatalytic hydrogen production (7.09 mmol g h ). Density functional theory (DFT) calculations established the electronic structures of Cu-I-bpy with a narrow band gap of 2.05 eV, indicating its semiconductive behavior, which is consistent with the experimental value of 2.00 eV. The proposed mechanism demonstrates that Cu I clusters of Cu-I-bpy serve as photoelectron generators to accelerate the copper(I) hydride interaction, providing redox reaction sites for hydrogen evolution. The highly stable cocatalyst-free and self-sensitized Cu-I-bpy provides new insights into the future design of cost-effective d -based MOFs for highly efficient and long-term solar fuels production.

Scaling in membrane distillation (MD) is a key issue in desalination of concentrated saline water, where the interface property between the membrane and the feed become critical. In this paper, a new slippery mechanism was explored as an innovative concept to understand the scaling behavior in membrane distillation for a soluble salt, NaCl. The investigation was based on a novel design of a superhydrophobic polyvinylidene fluoride (PVDF) membrane with micro-pillar arrays (MP-PVDF) using a micromolding phase separation (µPS) method. The membrane showed a contact angle of 166.0 ± 2.3° and the sliding angle of 15.8 ± 3.3°. After CF4 plasma treatment, the resultant membrane (CF4-MP-PVDF) showed a reduced sliding angle of 3.0 o. In direct contact membrane distillation (DCMD), the CF4-MP-PVDF membrane illustrated excellent anti-scaling in concentrating saturated NaCl feed. Characterization of the used membranes showed that scaling due to NaCl crystals and possible membrane wetting occurred on the control PVDF and MP-PVDF membranes, but not on the CF4-MP-PVDF membrane. To understand this phenomenon, a "slippery" theory was introduced and correlated the sliding angle to the slippery surface of CF4-MP-PVDF and its anti-scaling property. This work provides a well-defined physical and theoretical platform for investigating scaling problems in membrane distillation and beyond.

The development of logical visible-light-driven heterogeneous photosystems for water splitting is a subject of new research. As the first example of a noble-metal-free photocatalyst for both H 2 and O 2 production, a high-nuclear {Cu I 24 (μ 3 -Cl) 8 (μ 4 -Cl) 6 }-based polyoxometalate (POM)@metal−organic framework (MOF) (ZZULI-1) is rationally designed to serve as a robust dualfunctionalized photocatalyst. ZZULI-1 exhibits highly efficient photocatalytic H 2 evolution (6614 μmol g −1 h −1 ) and O 2 evolution (1032 μmol g −1 calculated for the first 6 min). The {Cu I 24 (μ 3 -Cl) 8 (μ 4 -Cl) 6 } clusters and mixed POMs not only work as the active units for H 2 and O 2 production, respectively, but also improve the effective electron transfer between the photosensitizer and ZZULI-1. The highly stable dual-functionalized ZZULI-1 affords new penetrations into the development of cost-effective high-nuclear cluster-based POM@MOFs for efficient solar-to-fuel generation.

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