Degradation Mechanism Research Articles

Revealing microstructural degradation mechanism induced by interdiffusion between Amdry365 coating and IN792 superalloy

Metallic coatings are widely employed to improve the oxidation resistance of superalloys. However, the interdiffusion between the metallic coatings and the superalloys leads to microstructural degradation in both. Some of the underlying degradation mechanisms are still elusive, e.g., the γ′ (Ni3Al) phase depletion in superalloys, where a large amount of γ′ precipitates are dissolved in the γ matrix even though the incoming Al from coatings indeed increases the Al content. Here, we investigated the interdiffusion behavior between the Amdry365 coating and the IN792 superalloy at 1100 °C, using multiple microscopic techniques and thermodynamics calculations. Our results showed an excellent agreement between experiments and thermodynamics simulations, indicating the dominant role of Al on the initial diffusion-induced phase transitions. We proposed the Al-Cr interference effect to account for the pile-up behavior of Cr and the reduced Al content near the coating/superalloy interface. The local phase equilibrium calculations revealed that the γ′ depletion in the superalloy is primarily attributed to the loss of γ′-forming elements, such as Ta and Ti. Our findings opened up an avenue for studies on the superalloy/coating interdiffusion, contributing to reducing this damaging impact

Proteasome-dependent degradation of histone H1 subtypes is mediated by its C-terminal domain.

Histone H1 is involved in chromatin compaction and dynamics. In human cells, the H1 complement is formed by different amounts of somatic H1 subtypes, H1.0-H1.5 and H1X. The amount of each variant depends on the cell type, the cell cycle phase, and the time of development and can be altered in disease. However, the mechanisms regulating H1 protein levels have not been described. We have analyzed the contribution of the proteasome to the degradation of H1 subtypes in human cells using two different inhibitors: MG132 and bortezomib. H1 subtypes accumulate upon treatment with both drugs, indicating that the proteasome is involved in the regulation of H1 protein levels. Proteasome inhibition caused a global increase in cytoplasmatic H1, with slight changes in the composition of H1 bound to chromatin and chromatin accessibility and no alterations in the nucleosome repeat length. The analysis of the proteasome degradation pathway showed that H1 degradation is ubiquitin-independent. The whole protein and its C-terminal domain can be degraded directly by the 20S proteasome in vitro. Partial depletion of PA28γ revealed that this regulatory subunit contributes to H1 degradation within the cell. Our study shows that histone H1 protein levels are under tight regulation to prevent its accumulation in the nucleus. We revealed a new regulatory mechanism for histone H1 degradation, where the C-terminal disordered domain is responsible for its targeting and degradation by the 20S proteasome, a process enhanced by the regulatory subunit PA28γ.

Insights into the hydrolysis/alcoholysis/ammonolysis mechanisms of ethylene naphthalate dimer using density functional theory (DFT) method

Hydrolysis, alcoholysis and ammonolysis are viable routes for the efficient degradation and recycling of polyethylene naphthalate (PEN) plastic waste. Various possible hydrolysis/alcoholysis/ammonolysis reaction pathways for the degradation mechanism of the ethylene naphthalate dimer were investigated using the density functional theory (DFT) B3P86/6-31++G(d,p). To determine the thermodynamic and kinetic parameters, geometric structure optimization and frequency calculation were performed on a range of intermediates, transition states, and products associated with the reaction. The calculation results show that the highest energy barrier of the main element reaction step in hydrolysis is about 169.0 kJ/mol, the lowest is about 151.0 kJ/mol for ammonolysis, and the second is about 155.0 kJ/mol for alcoholysis. The main hydrolysis products of the ethylene naphthalate dimer are 2,6-naphthalenedicarboxylic acid and ethylene glycol; the main products of alcoholysis are dimethyl naphthalene-2,6-dicarboxylate and ethylene glycol, and the main products of ammonolysis are naphthalene-2,6-dicarboxamide and ethylene glycol. Furthermore, in the process of ethylene naphthalate dimer hydrolysis/alcoholysis/ammonolysis, the decomposition reaction in the NH3 atmosphere is better than that in methanol, and the reaction in CH3OH is better than that in the H2O molecular environment, and the increase in reaction temperature can increase its spontaneity. Our study presents the molecular mechanism of PEN hydrolysis/alcoholysis/ammonolysis and provides a reference for studying the degradation of other plastic wastes.

Effect of wet-dry history on performances of dense asphalt mixture: experimental investigation and predicting model

Asphalt pavement experiences various wet-dry histories in the service stage. However, the influence of wet-dry history on asphalt mixture is unknown. Therefore, to clarify the performance degradation mechanism and predict the performance of asphalt mixture under the action of wet-dry history, the creep-recovery test, indirect tensile stiffness modulus test and indirect tensile strength test were conducted at different temperatures. The finite element method was adopted to analyze the moisture diffusing profile inside the specimen after wet-dry cycles. A moisture damage model considering the soaking time and repeated characteristics was developed to predict the damaged properties. Results show that wet-dry cycles cause a slight mass loss of asphalt mixture. Wet-dry cycling action leads to the increment in high-temperature deformation, and reductions in stiffness modulus and tensile strength. The increase of high-temperature deformation is primarily caused by viscoplastic component. Even if the soaking time is short, high moisture damage occurs while the wet-dry cycle is sufficient. Numerical simulations show that the moisture concentration profiles inside asphalt mixture vary under different wet-dry histories, leading to variations in the damage zone. The degree of damage is also closely related to the acting time of moisture. The critical immersion time of the dense asphalt mixture (about 43hours) was determined in this study. When the immersion period is shorter than the critical immersion time, the strength loss is greater than the modulus. On the contrary, the degree of modulus damage is higher than that of strength. Considering the actual rainfall climate in China, the strength damage of the on-site asphalt mixture in the field predominates. The proposed model could reflect the weakening trends of modulus and strength. It has good universal applicability in predicting the damaged Marshall stability, modulus, and strength at different temperatures.

An Improved Hot Spot Mitigation Approach for Photovoltaic Modules Under Mismatch Conditions

The reduction of photogenerated current in photovoltaic (PV) cells due to various degradation mechanisms leads to hot spot (HS) generation, resulting in serious safety and reliability concerns. This article presents a novel hot spot mitigation circuit (HSMC), which effectively counters HS formation in cells under mismatch situations, improving the reliability of the entire PV arrangement. The effectiveness of the proposed HSMC is compared extensively with the conventional bypass diode (BPD) through experimentation on a 3×1 PV string and a 3×3 series-parallel (SP) PV array in an outdoor setting. Detailed thermographic analysis showed that the maximum temperature of the PV module under low shading levels reached 119.16% and 54.11% higher with the traditional BPD than with the proposed HSMC when tested on a 3×1 PV string and 3×3 SP PV array, respectively. This indicates that the mismatched cell was subjected to elevated temperatures with BPD. Moreover, the experimental results confirm that the proposed HSMC resulted in enhanced power output and a significant reduction of power loss in the bypass path of the shaded module under increased shading levels compared to the traditional BPD. The proposed HSMC reduced mismatch loss by up to 89.82% when tested on a 3×1 PV string.

The role of autophagy in mitigating osteoarthritis progression via regulation of chondrocyte apoptosis: A review.

Osteoarthritis (OA) is the most prevalent chronic joint disease with an immense socioeconomic burden; however, no treatment has achieved complete success in effectively halting or reversing cartilage degradation, which is the central pathophysiological feature of OA. Chondrocytes loss or dysfunction is a significant contributing factor to the progressive cartilage deterioration as these sole resident cells have a crucial role to produce extracellular matrix proteins, thus maintaining cartilage structure and homeostasis. It has been previously suggested that death of chondrocytes occurring through apoptosis substantially contributes to cartilage degeneration. Although the occurrence of apoptosis in osteoarthritic cartilage and its correlation with cartilage degradation is evident, the causes of chondrocyte apoptosis leading to matrix loss are still not well-understood. Autophagy, an intracellular degradative mechanism that eliminates dysfunctional cytoplasmic components to aid cell survival in unfavourable conditions, is a potential therapeutic target to inhibit chondrocyte apoptosis and reduce OA severity. Despite accumulating evidence indicating significant cytoprotective effects of autophagy against chondrocyte apoptosis, the mechanistic link between autophagy and apoptosis in chondrocytes remains to be further explored. In this review, we summarize the relevant mechanistic events that perpetuate chondrocyte apoptosis and highlight the prominent role of autophagy in modulating these events to mitigate OA progression.

Towards More Sustainable Aqueous Zinc‐Ion Batteries

AbstractAqueous zinc‐ion batteries (AZIBs) are considered as the promising candidates for large‐scale energy storage because of their high safety, low cost and environmental benignity. The large‐scale applications of AZIBs will inevitably result in a large amount of spent AZIBs, which not only induce the waste of resources, but also pose environmental risks. Therefore, sustainable AZIBs have to be considered to minimize the risk of environmental pollution and maximize the utilization of spent compounds. Herein, this minireview focuses on the sustainability of AZIBs from material design and recycling techniques. The structure and degradation mechanism of AZIBs are discussed to guide the recycling design of the materials. Subsequently, the sustainability of component materials in AZIBs is further analysed to pre‐evaluate their recycling behaviors and mentor the selection of more sustainable component materials, including active materials in cathodes, Zn anodes, and aqueous electrolytes, respectively. According to the features of component materials, corresponding green and economic approaches are further proposed to realize the recycling of active materials in cathodes, Zn anodes and electrolytes, respectively. These advanced technologies endow the recycling of component materials with high efficiency and a closed‐loop control, ensuring that AZIBs will be the promising candidates of sustainable energy storage devices. This review will offer insight into potential future directions in the design of sustainable AZIBs.

Towards More Sustainable Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) are considered as the promising candidates for large-scale energy storage because of their high safety, low cost and environmental benignity. The large-scale applications of AZIBs will inevitably result in a large amount of spent AZIBs, which not only induce the waste of resources, but also pose environmental risks. Therefore, sustainable AZIBs have to be considered to minimize the risk of environmental pollution and maximize the utilization of spent compounds. Herein, this minireview focuses on the sustainability of AZIBs from material design and recycling techniques. The structure and degradation mechanism of AZIBs are discussed to guide the recycling design of the materials. Subsequently, the sustainability of component materials in AZIBs is further analysed to pre-evaluate their recycling behaviors and mentor the selection of more sustainable component materials, including active materials in cathodes, Zn anodes, and aqueous electrolytes, respectively. According to the features of component materials, corresponding green and economic approaches are further proposed to realize the recycling of active materials in cathodes, Zn anodes and electrolytes, respectively. These advanced technologies endow the recycling of component materials with high efficiency and a closed-loop control, ensuring that AZIBs will be the promising candidates of sustainable energy storage devices. This review will offer insight into potential future directions in the design of sustainable AZIBs.

A Review of Weathering Studies in Plastics and Biocomposites—Effects on Mechanical Properties and Emissions of Volatile Organic Compounds (VOCs)

Polymeric materials undergo degradation when exposed to outdoor conditions due to the synergistic effects of sunlight, air, heat, and moisture. The degradation can lead to a decline in mechanical properties, fading, surface cracking, and haziness, attributed to the cleavage of the polymer chains and oxidation reactions. Accelerated weathering testing is a useful technique to evaluate the comparative photodegradation of materials within a reasonable timeframe. This review gives an overview of the different degradation mechanisms occurring in conventional plastics and bio-based materials. Case studies on accelerated weathering and its effect on the mechanical properties of conventional plastics and biocomposites are discussed. Different techniques for analysing volatile organic emissions (VOCs) have been summarized and studies highlighting the characterization of VOCs from aged plastics and biocomposites after aging have been cited.

Improving the hydrostability of zeolitic imidazolate framework coatings using a facile silk fibroin protein modification method

AbstractZeolitic imidazolate frameworks (ZIFs) are an important subclass of metal-organic frameworks (MOFs) with zeolite-type topology, which can be fabricated under ambient synthesis conditions. However, the applications of ZIFs are commonly limited due to the weak hydrostability of their metal–ligand coordination bonds, particularly under humid and aqueous conditions. In this work, as an example, the hydrolysis behaviours of ZIF-L with a special focus on ZIF-L coatings were tested at aqueous conditions with a wide range of pHs to systematically study and fundamentally understand their structural stability and degradation mechanism. Pristine ZIF-L powder and ZIF-L coatings were severely damaged after only 24 h in aqueous media. Interestingly, the ZIF-L coatings showed two distinct hydrolyzation pathways regardless of pH conditions, exhibiting either a ring-shaped etching or unfolding behaviours. While the ZIF-L powders were hydrolyzed almost identically across all pH conditions. With this new understanding, a facile silk fibroin (SF) protein modification method was developed to enhance the hydrostability of ZIF-L coatings in aqueous media. The effect of protein concentration on surface coating was systemically studied. ZIF-L coating retained its surface morphology after soaking in water and demonstrated switchable super wetting properties and superior separation performance for oil/water mixture. As a result, the quick SF protein modification significantly enhanced the stability of ZIF-L coatings under various pHs, while retaining their switchable wetting property and excellent separation performance.

Effect of Thermal Cycling or Simulated Gastric Acid on the Surface Characteristics of Dental Ceramic Materials

(1) Background: The presence of various dental ceramic materials with different chemical compositions complicates clinicians’ decision making, especially in cases with a highly acidic environment appearing in patients suffering from gastroesophageal reflux disease or other eating disorders. Thermal alterations in the oral cavity can also affect surface structure and roughness, resulting in variations in both degradation mechanisms and/or bacteria adhesion. The aim of the present in vitro study was to evaluate the effect of thermal cycling and exposure to simulated gastric acid on the surface roughness of different ceramics; (2) Methods: Five groups of different ceramics were utilized, and twenty specimens were fabricated for each group. Specimens were either thermocycled for 10,000 cycles in distilled water or immersed in simulated gastric acid for 91 h. The evaluation of surface roughness was performed with optical profilometry, while scanning electron microscopy, X-ray diffraction analysis and inductively coupled plasma atomic emission spectroscopy were also performed; (4) Conclusions: Based on the combination of the surface roughness profile and structural integrity, zirconia specimens presented the smallest changes after immersion in simulated gastric acid followed by lithium disilicate materials. Zirconia-reinforced lithium silicate ceramic presented the most notable changes in microstructure and roughness after both treatments.

The Study on Single-Event Effects and Hardening Analysis of Frequency Divider Circuits Based on InP HBT Process

The single-event effects (SEEs) of frequency divider circuits and the radiation tolerance of the hardened circuit are studied in this paper. Based on the experimental results of SEEs in InP HBTs, a transient current model for sensitive transistors is established, taking into account the influence of factors such as laser energy, base-collector junction voltage, and radiation position. Moreover, the SEEs of the (2:1) static frequency divider circuit with the InP DHBT process are simulated under different laser energies by adding the transient current model at sensitive nodes. The effect of the time relationship between the pulsed laser and clock signal are discussed. Changes in differential output voltage and the degradation mechanism of unhardened circuits are analyzed, which are mainly attributed to the cross-coupling effect between the transistors in the differential pair. Furthermore, the inverted output is directly connected to the input, leading to a feedback loop and causing significant logic upsets. Finally, an effective hardened method is proposed to provide redundancy and mitigate the impacts of SEEs on the divider. The simulation results demonstrate a notable improvement in the radiation tolerance of the divider.

Ni-Cu Alloyed Austempered Ductile Iron Resistance to Multifactorial Wear

The paper provides a discussion on the results of studies of the effect exerted by combined degradation factors typical of four types of wear: abrasion, impact–abrasion, tribocorrosion, and impact–abrasion–corrosion, conducted for chain wheels made of Ni-Cu alloyed austempered ductile iron. The studies consisted of determining the content of retained austenite in the structure of the cast irons in question, establishing the measures of wear following wear testing, and identifying the basic surface degradation mechanisms observed in the chain wheels tested following multifactorial wear processes. The chain wheels made of ADI were found to have sustained the greatest damage under the impact–abrasion–corrosion (three-factor) wear scenario, while the wear was least advanced in the abrasion (one-factor) wear case. Another observation derived from the studies is that the combined effect of dynamic forces, corrosion, and quartz sand-based abrasives causes increased surface degradation in the cast iron grades taken into consideration compared to processes characterised by a reduced number of degradation factors (i.e., one- or two-factor wear processes). Additional hardness tests and XRD analyses revealed that a distinctive effect attributable to combined degradation factors on the surface hardness increased value and implied that bench testing was followed by phase transition.

Evaluation of the Thermal, Chemical, Mechanical, and Microbial Stability of New Nanohybrids Based on Carboxymethyl-Scleroglucan and Silica Nanoparticles for EOR Applications

Scleroglucan (SG) is resistant to harsh reservoir conditions such as high temperature, high shear stresses, and the presence of chemical substances. However, it is susceptible to biological degradation because bacteria use SG as a source of energy and carbon. All degradation effects lead to viscosity loss of the SG solutions, affecting their performance as an enhanced oil recovery (EOR) polymer. Recent studies have shown that nanoparticles (NPs) can mitigate these degradative effects. For this reason, the EOR performance of two new nanohybrids (NH-A and NH-B) based on carboxymethyl-scleroglucan and amino-functionalized silica nanoparticles was studied. The susceptibility of these products to chemical, mechanical, and thermal degradation was evaluated following standard procedures (API RP 63), and the microbial degradation was assessed under reservoir-relevant conditions (1311 ppm and 100 °C) using a bottle test system. The results showed that the chemical reactions for the nanohybrids obtained modified the SG triple helix configuration, impacting its viscosifying power. However, the nanohybrid solutions retained their viscosity during thermal, mechanical, and chemical degradation experiments due to the formation of a tridimensional network between the nanoparticles (NPs) and the SG. Also, NH-A and NH-B solutions exhibited bacterial control because of steric hindrances caused by nanoparticle modifications to SG. This prevents extracellular glucanases from recognizing the site of catalysis, limiting free glucose availability and generating cell death due to substrate depletion. This study provides insights into the performance of these nanohybrids and promotes their application in reservoirs with harsh conditions.

Experimental investigation on tensile behavior of CFRP bolted joints subjected to hydrothermal aging

Abstract With the help of bolted joints to assemble a complex structure, carbon fiber reinforced polymer composite (CFRP) is widely used in various fields. However, stress concentration around holes at the bolted joints leads to a decrease in bearing capacity. Composites often result in mechanical degradation subjected to a complex hydrothermal environment. Therefore, to study the tensile behavior of CFRP bolted joints subjected to hydrothermal aging, the tensile tests are conducted carefully. The influence of aging time and temperature on tensile strength is investigated based on the response history, strain contour, and failure morphology. The failure mechanism is revealed via digital image correlation technology. Finally, the experimental results demonstrate that the bearing capacity of the structure in hydrothermal aging decreases significantly. Compared with the unaged specimens, the peak force of the specimens aged for 6 weeks at 25°C and 65°C is reduced by 22.79% and 35.63%, respectively. Under both the unaged and aged, the same bearing failure is found in the tensile tests of CFRP single-bolt single-lap joints.

Degradation mechanism of measuring performance of Optical Particle Counter under temperature-pressure coupling effect

Abstract To investigate the degradation mechanism of measuring the performance of an Optical Particle Counter (OPC) under temperature-pressure coupling, this study first establishes a theoretical calculation model of gas refractive index, and then elucidates the comprehensive influence mechanism of temperature and pressure on gas optical properties. Furthermore, the experimental measurement technique and measuring device for gas refractive index are built. By comparing the theoretical and experimental results in the temperature range of 48-560°C and the pressure range of 0.9-4.6 MPa, the difference between the two errors is just 0.05%, indicating the accuracy of the theoretical model of the refractive index of gas. Secondly, a dynamic model of Optical Measurement Volume (OMV) under high-temperature and high-pressure conditions was established using geometrical optics theory, and the impacts of gas temperature and pressure variations on OPC measurement performance were investigated. The gas temperature (100-1000 °C) and pressure (1-4.6 MPa) are shown to have opposing effects on the OMV, with gas pressure being more relevant. Finally, in order to eliminate the effect of gas refractive index change on the optical measurement performance of OPC, a parallel light model is proposed to solve the problem of the degradation of OPC measurement performance under temperature and pressure coupling conditions.

Fenton reaction in the process of “Laser + Fe” mode excited plasma for Rhodamine B degradation

The spectral emission of laser-induced plasma in water has a broadband continuum containing ultraviolet light, which can be used as a novel light source for the degradation of organic compounds. We studied the degradation process of the organic dye Rhodamine B (RhB) using plasma light source excited by the “Laser + Fe” mode. Spectral analysis and reaction kinetics modelling were used to study the degradation mechanism. The degradation process using this light source could be divided into two stages. The initial stage was mainly photocatalytic degradation, where ultraviolet light broke the chemical bond of RhB, and then RhB was degraded by the strong oxidising ability of ·OH. As the iron and hydrogen ion concentrations increased, the synergistic effect of photocatalysis and the Fenton reaction further enhanced the degradation rate in the later stage. The plasma excited by the “Laser + Fe” mode achieved photodegradation by effectively enhancing the ultraviolet wavelength ratio of the emission spectrum and triggered the Fenton reaction to achieve rapid organic matter degradation. Our findings indicate that the participation of the Fenton reaction can increase the degradation rate by approximately 10 times. Besides, the impact of pH on degradation efficiency demonstrates that both acidic and alkaline environments have better degradation effects than neutral conditions; this is because acidic environments can enhance the Fenton reaction, while alkaline environments can provide more ·OH.

Construction of Phosphorus‐Doped g‐C3N4 Nanosheets and Activation of Sodium Percarbonate for Degradation of Organic Pollutants in Wastewater

AbstractA novel phosphorus‐doped graphitic carbon nitride nanosheets (PS‐CN) photocatalyst was prepared by thermal polycondensation and thermal stripping method, and its physicochemical properties were characterized. The results show that PS‐CN formed a thin sheet and multi‐cavity structure by thermal delamination that could enhance the surface area, light reception, and adsorption capacity. The prepared PS‐CN activated sodium percarbonate system (PS‐CN/SPC) was developed for the degradation of dyeing wastewater with methylene blue (MB) as the target pollutant and the degradation mechanism was analyzed. At room temperature (20 °C), the degradation rate of MB in PS‐CN/SPC system within 10 min (88.13 %) was three times that of pure g‐C3N4. In addition, the MB was completely degraded under visible light within 60 min. Moreover, PS‐CN exhibited excellent reusability that the degradation rates of MB have remained above 96 % in five consecutive cycles. The free radical quenching experiments showed that hole (h+), hydroxyl radical (•OH) and superoxide radical (•O2−) all participated in MB degradation, and •OH was the main active species. The PS‐CN/SPC system would provide a high‐value solution for the treatment of dye wastewater due to the low cost of raw materials, superior photocatalytic activity, simple synthesis method, and reusability of the catalyst.

Potential mechanisms of propionate degradation and methanogenesis in anaerobic digestion coupled with microbial electrolysis cell system: Importance of biocathode

Microbial electrolysis cells (MEC) have the potential for enhancing the efficiency of anaerobic digestion (AD). In this study, microbiological and metabolic pathways in the biocathode of anaerobic digestion coupled with microbial electrolysis cells system (AD-MEC) were revealed to separate bioanode. The biocathode efficiently degraded 90 % propionate within 48 h, leading to a methane production rate of 3222 mL·m−2·d-1. The protein and heme-rich cathodic biofilm enhanced redox capacity and facilitated interspecies electron transfer. Key acid-degrading bacteria, including Dechloromonas agitata, Ignavibacteriales bacterium UTCHB2, and Syntrophobacter fumaroxidans, along with functional proteins such as cytochrome c and e-pili, established mutualistic relationships with Methanothrix soehngenii. This synergy facilitated a multi-pathway metabolic process that converted acetate and CO2 into methane. The study sheds light on the intricate microbial dynamics within the biocathode, suggesting promising prospects for the scalable integration of AD-MEC and its potential in sustainable energy production.

Recent Developments in Porphyrin-Based Metal–Organic Framework Materials for Water Remediation under Visible-Light Irradiation

Access to clean drinking water is a basic requirement, and eliminating pollutants from wastewater is important for saving water ecosystems. The porous structure and surface characteristics of metal–organic frameworks (MOFs) can function as a perfect scaffold for removing toxic compounds from wastewater. Porphyrins are promising building blocks for constructing MOFs. Porphyrin-based metal–organic frameworks (P-MOFs) have been fabricated using porphyrin ligands, metal clusters, or ions. These materials can harvest light from a wide region of the solar spectrum, and their framework morphology and physicochemical properties can be controlled by changing their peripheral subunits or metal ions. These porous crystalline materials have generated interest because of their distinctive characteristics, including large permanent porosity, interesting surface morphology, broad conformational diversity, high photostability, and semiconducting nature. This article discusses the recent progress and usefulness of P-MOFs. The fabrication procedures of P-MOFs are discussed, followed by the adsorptive and photocatalytic removal of contaminants from wastewater. The relationships between the geometries of P-MOFs and their light-harvesting and charge-transfer mechanisms for the photocatalytic degradation of pollutants are highlighted. Finally, some future perspectives and obstacles in the photodegradation usage of P-MOFs are discussed, along with feasible research directions to standardize efficient photocatalysts for improved photodegradation for water treatment.